Craig Sager, an exuberant sideline reporter for National Basketball Association television broadcasts who was as well known for his outlandishly garish outfits as for the questions he asked coaches and players, died on Thursday in Atlanta. He was 65.

The cause was leukemia, according to a spokesman for Turner Sports. After receiving the diagnosis in 2014, Mr. Sager continued to work occasionally during what became a highly public illness. He received blood transfusions to be strong enough to travel to some games, and returned to a hospital after others.

He last appeared in a game broadcast in June and canceled plans to work for NBC at the Summer Olympics in Brazil in August to continue treatment.

Mr. Sager brought deep knowledge of basketball and a fun-loving spirit to his work. He was known for working behind the scenes to find news that he could use in his on-air reports or give to announcing colleagues like Marv Albert and Reggie Miller.