Killian Hayes is a French-American professional basketball player currently with the Brooklyn Nets of the NBA. Born in Florida but raised in France due to his father's basketball career, Hayes demonstrated early talent playing for Cholet in France. He made his debut with Cholet's senior team at 16. He later played in Germany for Ulm during the 2019-20 season before entering the NBA.
On July 27, 2001, Killian Hayes was born in Lakeland, Florida. He is the son of former basketball player DeRon Hayes.
In 2016, Killian Hayes began playing for Espoirs Cholet in the French under-21 league.
In April 2017, Killian Hayes shared MVP honors with Addison Patterson at the Jordan Brand Classic International Game.
On October 21, 2017, Killian Hayes debuted with the Cholet senior team at 16 years old.
In 2017, Killian Hayes was named MVP of the FIBA U16 European Championship.
In 2017, Killian Hayes won the gold medal and earned the MVP honors playing for France at the FIBA U16 European Championship.
In February 2018, Killian Hayes participated in the Basketball Without Borders camp during NBA All-Star Weekend in Los Angeles.
On May 15, 2018, Killian Hayes recorded 12 points and six assists in a win over Le Mans.
On September 22, 2018, Killian Hayes scored 12 points in a loss to Strasbourg.
In 2018, Killian Hayes led his team to a silver medal at the FIBA Under-17 World Cup.
In 2018, Killian Hayes won a silver medal and was named to the All-Star Five at the FIBA Under-17 Basketball World Cup.
On May 30, 2019, Killian Hayes tallied a season-high 17 points, five rebounds, and five steals in a loss to Élan Chalon.
In July 2019, the French Federation of Basketball imposed a six-game suspension on Killian Hayes for not playing in the 2019 FIBA U20 European Championship.
On August 2, 2019, Killian Hayes signed a three-year contract with ratiopharm Ulm of the Basketball Bundesliga (BBL).
On December 1, 2020, Killian Hayes signed his rookie scale contract with the Detroit Pistons.
On January 4, 2021, Killian Hayes suffered a hip injury during a game against the Milwaukee Bucks.
On February 11, 2022, Killian Hayes recorded a career-high 12 assists in a loss to the Charlotte Hornets.
On December 28, 2022, Killian Hayes was ejected from a game against the Orlando Magic following an altercation with Mo Wagner.
On February 8, 2024, Killian Hayes was waived by the Detroit Pistons.
On September 20, 2024, Killian Hayes signed with the Brooklyn Nets.
On February 19, 2025, Killian Hayes signed a 10-day contract with Brooklyn after Bojan Bogdanović was waived.