Olin Hacker (born 21 May 1996) is an American track and field athlete who competes as a long distance runner.

[1] Olin attended Madison West High School in Madison, Wisconsin and won state cross country titles in 2013 and 2014, as well becoming state champion in the mile and two-mile distances.

He has two older brothers, Sam and Wilson and a sister called Vivian, all of whom have competed in athletics.

[2][3] Hacker won the NCAA title outdoors over 5000 metres in Eugene, Oregon in 2022 in a time of 13:27.73, competing for the University of Wisconsin.

[7] He finished as runner-up in the 3000 metres at the US National Indoors Championships in New Mexico in February 2024, in a time of 7:56.22.