Last Updated on October 12, 2026 by Candida Lucia
Isaiah Hartenstein is a German-American professional basketball player who plays for the Oklahoma City Thunder in the NBA. Born on May 5, 1998, in Eugene, Oregon, Hartenstein grew up in a family with strong connections to professional basketball. His father, Florian Hartenstein, was a professional basketball player and coach in Germany, while his mother, Theresa Hartenstein, worked as a dance and cheerleading coach.
Beyond his successful basketball career, Isaiah Hartenstein’s family includes his wife, Kourtney Kellar, their son, Elijah James Hartenstein, his parents, and his older sister, Jasmine Hartenstein. His family played a central role in his journey from Oregon to Germany and eventually the NBA, where he became a champion with the Oklahoma City Thunder in 2025. Here is everything publicly known about Isaiah Hartenstein’s wife, children, parents, and siblings.
Isaiah Hartenstein’s Wife: Who Is Kourtney Kellar?
Isaiah Hartenstein is married to Kourtney Kellar, an American model, social media influencer, and former boxing ring girl. The couple began dating in 2019, became engaged in April 2022, and married on July 29, 2023.
Kourtney Kellar was born and raised in Dallas, Texas, where she developed an interest in fashion and modeling.
She attended Henderson State University in Arkansas, graduating in 2014 with a degree in athletic training.
While attending college, Kellar began modeling to help pay for her education. She initially worked with retailers such as Dillard’s and Walmart before pursuing larger modeling opportunities.
In 2017, she won the Miss Texas International pageant, an achievement that helped expand her modeling career.
She subsequently worked with several modeling agencies and appeared at events including Miami Swim Week and New York Fashion Week.
Kellar also gained attention as a ring girl at major professional boxing events, including fights involving Canelo Álvarez and Jake Paul.
Beyond modeling, she has developed a substantial following on Instagram and TikTok, where she shares fashion content, family moments, and experiences as the wife of an NBA player.
How Did Isaiah Hartenstein Meet Kourtney Kellar?
Isaiah Hartenstein and Kourtney Kellar first connected through Instagram in 2019.
According to Kellar’s interview with the New York Post, Hartenstein sent her a direct message complimenting her smile.
Unlike many messages she received about her physical appearance, his approach attracted her attention because she considered it respectful and thoughtful.
At the time, Hartenstein was playing for the Houston Rockets, while Kellar was living in Dallas.
The two began communicating regularly and participated in several FaceTime conversations before meeting in person.
They eventually arranged their first date at a restaurant, and their relationship developed from there.
Despite the demands of Hartenstein’s professional basketball career, the couple remained together as he moved between NBA teams.
When Did Isaiah Hartenstein Get Married?
Isaiah Hartenstein married Kourtney Kellar on July 29, 2023, in Newport Beach, California.
The couple held their wedding aboard the Endless Dreams yacht, celebrating with approximately 60 family members and close friends.
According to an exclusive interview published by People, the ceremony featured a romantic sunset setting overlooking the Pacific Ocean.
Kellar wore a wedding gown designed by Rebecca Schoneveld, while Hartenstein wore a black tuxedo.
The wedding took place approximately 15 months after Hartenstein proposed during a photoshoot on a beach in Malibu in April 2022.
Their marriage came while Isaiah was playing for the New York Knicks, before his move to the Oklahoma City Thunder in 2024.
As of now, Isaiah Hartenstein and Kourtney Kellar remain married and are raising their family together.
Isaiah Hartenstein’s Children: Meet His Son Elijah James
Isaiah Hartenstein has one publicly confirmed child, a son named Elijah James Hartenstein, whom he shares with his wife, Kourtney Kellar.
Elijah James Hartenstein – Isaiah Hartenstein’s Son
Elijah James Hartenstein was born on May 23, 2024, approximately ten months after his parents married.
His birth marked an important milestone in Hartenstein’s personal life, making him a father for the first time.
The couple shared their happiness through social media, introducing their son to followers and celebrating their new responsibilities as parents.
Elijah was born during the period when Isaiah was playing for the New York Knicks.
Just two months later, Hartenstein signed a three-year, $87 million contract with the Oklahoma City Thunder, prompting the family to relocate.
Becoming a father therefore coincided with one of the most important professional transitions of his basketball career.
How Isaiah Hartenstein Celebrated the NBA Championship With His Son
One of the most memorable family moments in Isaiah Hartenstein’s career occurred on June 22, 2025, when the Oklahoma City Thunder defeated the Indiana Pacers in Game 7 of the NBA Finals.
Following the victory, Hartenstein celebrated on the court with his wife and young son.
During the championship trophy presentation, Isaiah held Elijah in his arms while speaking with reporters.
The child appeared to be sleeping through much of the celebration, creating a lighthearted moment that attracted attention from basketball fans.
Thunder teammate Shai Gilgeous-Alexander also interacted with Hartenstein during the celebration as the players shared their excitement.
The moment highlighted the significance of winning an NBA championship while raising a young family.
As of now, Elijah James remains the couple’s only publicly confirmed child.
Isaiah Hartenstein’s Parents: Meet Florian and Theresa Hartenstein
Isaiah Hartenstein was born to Florian Hartenstein and Theresa Hartenstein in Eugene, Oregon.
His parents met while Florian was pursuing basketball opportunities in the United States and Theresa was attending the University of Oregon.
Both eventually became involved in professional sports, although in different fields.
Florian pursued basketball, while Theresa developed a career in dance and cheerleading coaching.
The couple raised two children: Jasmine Hartenstein and Isaiah Hartenstein.
Isaiah Hartenstein’s Father: Florian Hartenstein
Florian Hartenstein is Isaiah Hartenstein’s father, a German-American former professional basketball player and coach.
He was born on August 13, 1977, in Mainz, Germany, to a German mother and an African American father.
Florian developed an interest in basketball as a teenager and eventually moved to the United States, where he played college basketball at the University of Oregon.
Following his collegiate career, he returned to Germany and established himself as a professional basketball player.
He played for several German basketball clubs, including the Gießen 46ers and Artland Dragons.
During his career, he competed as a center, using his height, strength, and physical style of play to contribute to his teams.
After retiring from professional basketball, Florian became involved in coaching and youth player development.
How Florian Hartenstein Influenced His Son’s Basketball Career
Florian Hartenstein played a central role in Isaiah’s development as a professional basketball player.
According to a June 2017 Bleacher Report feature, basketball was a regular part of the family’s life from Isaiah’s earliest childhood.
Florian recalled that their home contained basketball-themed decorations and a basketball hoop, allowing his son to develop an interest in the game naturally.
When Isaiah was approximately 11 years old, the family relocated from Oregon to Germany, where Florian was playing professionally.
The move allowed Isaiah to enter Germany’s organized youth basketball system.
Florian eventually became involved in coaching his son through the Artland Dragons organization.
Rather than developing Isaiah exclusively as a traditional center, he encouraged him to improve his passing, dribbling, and shooting.
Florian believed that learning skills normally associated with guards would make his son a more versatile basketball player.
In an interview published by Sky Sport Germany in 2025, Isaiah acknowledged the sacrifices his parents made to support his basketball ambitions.
He explained that his father’s decision to leave coaching responsibilities in Germany and help him pursue opportunities in the United States was particularly important.
The two also briefly played together professionally in Germany, giving Isaiah an unusual opportunity to share the court with his father.
Isaiah Hartenstein’s Mother: Theresa Hartenstein
Theresa Hartenstein is Isaiah Hartenstein’s mother, an American former dance and cheerleading coach originally from Oregon.
She met Florian while attending the University of Oregon, and the couple eventually married and started their family.
Theresa initially remained in Oregon with their children while Florian pursued professional basketball opportunities overseas.
However, the family eventually decided to reunite in Germany when Isaiah was approximately 11 years old.
According to her interview with Bleacher Report, Theresa believed it was more important for the children to grow up with both parents present than to remain separated because of Florian’s basketball career.
After relocating to Germany, she became involved in professional dance and cheerleading.
In 2009, Theresa began working with the Flames Dancers, the cheerleading squad associated with the Artland Dragons basketball organization.
She helped train dancers and develop performances for basketball games and other events.
Theresa also coached her daughter, Jasmine, who followed her into dancing and choreography.
She continued her involvement with the Flames Dancers until 2020.
How Theresa Hartenstein Supported Isaiah’s NBA Dream
Theresa Hartenstein has remained an important source of encouragement throughout her son’s basketball career.
During Isaiah’s childhood, she recognized his passion for basketball and supported his decision to pursue the sport seriously.
In interviews, she recalled that Isaiah was interested in basketball even as a toddler and frequently carried a ball wherever he went.
When he began receiving opportunities to compete at higher levels, Theresa supported his development and the family’s international moves.
She also remained involved when Isaiah entered the NBA in 2018.
Throughout his professional career, Theresa and Florian have attended important games and celebrated major milestones.
In June 2025, both parents attended Oklahoma City’s playoff celebrations and later celebrated their son’s NBA championship.
The experience represented the fulfillment of a dream the family had supported for many years.
Isaiah Hartenstein’s Siblings: Meet His Older Sister Jasmine
Isaiah Hartenstein has one sibling, an older sister named Jasmine Hartenstein.
Their sibling relationship is confirmed in a May 2026 family profile published by People, which identifies Jasmine and Isaiah as the two children of Florian and Theresa Hartenstein.
Jasmine Hartenstein – Isaiah Hartenstein’s Older Sister
Jasmine Hartenstein was born in 1992, making her approximately six years older than Isaiah.
Like her younger brother, Jasmine grew up in a household closely connected to professional sports.
However, she followed a different athletic and creative path.
Inspired by her mother, Theresa, Jasmine developed an interest in dancing and choreography.
She became a dancer and performer with the Flames Dancers, the cheerleading team associated with the Artland Dragons in Germany.
During her involvement with the organization, Jasmine also worked with her mother, who served as a dance coach.
She subsequently developed her own career in dance, performance, and choreography.
In 2022, Jasmine relocated to the United States, where she continued pursuing professional opportunities in choreography.
Although she has maintained a relatively private public profile compared with her NBA-playing brother, her background in dance reflects the family’s broader involvement in athletics and performance.
Does Jasmine Hartenstein Have Children?
Yes. Jasmine Hartenstein has a son named Shawn Michael, who was born on January 17, 2016.
This makes Isaiah Hartenstein an uncle.
According to a June 2025 People profile, Florian Hartenstein has developed a close relationship with his grandson.
He has participated in basketball activities with Shawn, attended school events, and spent time with him during family outings.
Florian has spoken publicly about the importance of positive male role models in children’s lives, drawing inspiration from his own childhood experiences.
Shawn Michael and Isaiah’s son, Elijah James, are the two grandchildren publicly identified in reports about Florian and Theresa Hartenstein.
Isaiah Hartenstein’s Ethnicity and Family Heritage
Isaiah Hartenstein has German, African American, and White American ancestry.
His father, Florian, was born in Germany to a German mother and an African American father, while his mother, Theresa, is a White American from Oregon.
According to a 2017 Andscape profile, Isaiah discussed how his appearance sometimes caused people to question his relationship with his father.
He explained that he identifies with his multicultural background and has occasionally challenged racial stereotypes.
Although born in the United States, Hartenstein spent important years of his childhood and teenage life in Germany.
He holds German and American citizenship and has represented Germany in international basketball competitions.
His upbringing exposed him to different cultures, languages, and basketball traditions, contributing to his development as both a person and an athlete.
How Isaiah Hartenstein’s Family Influenced His NBA Career
Isaiah Hartenstein’s professional journey began in Germany, where he developed his basketball skills through the youth system of the Artland Dragons.
His father’s guidance helped him become a versatile center capable of passing and handling the basketball.
He later joined Žalgiris Kaunas in Lithuania, gaining professional experience before declaring for the 2017 NBA Draft.
Hartenstein was selected with the 43rd overall pick by the Houston Rockets.
He made his NBA debut in 2018 and subsequently played for several organizations, including the Denver Nuggets, Cleveland Cavaliers, Los Angeles Clippers, and New York Knicks.
His performances with the Knicks helped establish him as a reliable starting center known for rebounding, passing, screening, and defensive contributions.
In July 2024, he joined the Oklahoma City Thunder on a three-year, $87 million contract.
The move occurred shortly after the birth of his son, Elijah, creating a new chapter in both his professional and family life.
In June 2025, Hartenstein helped Oklahoma City win the NBA championship, achieving a lifelong ambition that his parents had encouraged since childhood.
The championship celebration became a family occasion, with his wife, child, and parents sharing in the achievement.
Frequently Asked Questions About Isaiah Hartenstein’s Family
Who is Isaiah Hartenstein’s wife?
Isaiah Hartenstein’s wife is Kourtney Kellar, an American model and social media influencer. They married on July 29, 2023, in Newport Beach, California.
How did Isaiah Hartenstein meet his wife?
Isaiah Hartenstein met Kourtney Kellar through Instagram in 2019. He sent her a direct message complimenting her smile, and they began dating after communicating online.
How many children does Isaiah Hartenstein have?
Isaiah Hartenstein has one publicly confirmed child, a son named Elijah James Hartenstein, born on May 23, 2024.
Who are Isaiah Hartenstein’s parents?
Isaiah Hartenstein’s parents are Florian Hartenstein, a former professional basketball player and coach, and Theresa Hartenstein, a former dance and cheerleading coach.
Who is Isaiah Hartenstein’s father?
His father is Florian Hartenstein, a German-American former basketball player who represented the University of Oregon and professional clubs in Germany before becoming a coach.
Who is Isaiah Hartenstein’s mother?
His mother is Theresa Hartenstein, an American former dance coach who worked with the Flames Dancers in Germany and helped raise Isaiah and his older sister.
How many siblings does Isaiah Hartenstein have?
Isaiah Hartenstein has one sibling, an older sister named Jasmine Hartenstein, who works in dance and choreography.
Does Isaiah Hartenstein have a brother?
No brother has been publicly identified. His parents have two documented children: Isaiah and his older sister, Jasmine.
Does Isaiah Hartenstein have a nephew?
Yes. His sister Jasmine has a son named Shawn Michael, born on January 17, 2016.
Is Isaiah Hartenstein German or American?
Isaiah Hartenstein is German-American. He was born in Eugene, Oregon, and grew up partly in Germany. He holds dual citizenship and has represented Germany internationally.
Where is Isaiah Hartenstein’s family from?
His father’s family has German and African American roots, while his mother’s family comes from Oregon in the United States.
Did Isaiah Hartenstein’s father play in the NBA?
No. Florian Hartenstein played college basketball at the University of Oregon and professionally in Germany, but he did not play in the NBA.
Candida Lucia is a sports journalist and NBA writer specializing in tactical game analysis, player development, and league coverage. With an eye for on-court execution and team dynamics, she delivers detailed breakdowns of strategy, roster updates, and key performance trends. Passionate about bringing readers closer to the game, Candida offers engaging insights on every aspect of the NBA season, from regular-season battles to the Finals.
