Jeffrey John Hornacek ( /ˈhɔrnəsɛk/; born May 3, 1963) is a retired American basketball player who played at the shooting guard position in the NBA from 1986–2000.

He attended Komarek Elementary School in North Riverside, Illinois, and Gurrie Middle School and Lyons Township High School in La Grange, Cook County, Illinois.

Redshirted at Iowa State University (ISU) in 1981, he was a team walk-on who played from 1982–1986. The son of a high school basketball coach, he became an all-conference player in the Big Eight Conference, playing for legendary coach Johnny Orr. As a point guard he guided the Cyclones to the Sweet 16 of the 1986 NCAA tournament. His shining moment came at the Metrodome in Minneapolis when, after first hitting a shot to tie the game and send it to overtime, Jeff hit the game winning shot in overtime, a 26-ft jumper at the buzzer, to give ISU its first NCAA tournament victory since 1944, beating Miami University, March 14, 1986, 81–79. Two days later, he led the Cyclones to the NCAA Tournament "Sweet Sixteen," in a 72–69 upset of second seed Michigan. Orr, who had previously left Michigan to coach at Iowa State, called it the greatest victory of his career. Hornacek left ISU with a Big-8 record of 665 career assists, still an Iowa State school record, and 1,313 career points. He was the fourth player in Cyclone basketball history to have his number retired when his No. 14 jersey was hung from the rafters of Hilton Coliseum in 1991.