Jason Brownlee attended East Mississippi Community College out of high school in 2018. His sophomore season saw him finish with 75 receptions (15 more than any other player), 1055 yards and 12 touchdown receptions. He was named to the NJCAA All-America first-team. After finishing his two years at the junior college, he transferred to Southern Mississippi.
In 2020, Brownlee led Southern Mississippi in receptions (34), receiving yards (610), and receiving touchdowns (5). The following season, Brownlee would again lead Southern Miss with a 46-643-8 stat line. He had twice the receptions of the next player and more than 400 receiving yards than any other player on the team. In 2022, Southern Mississippi moved down to the Sun Belt conference and Brownlee led the team with 55 receptions for 891 receiving yards and 8 receiving touchdowns. For his career, he finished fifth in Southern Mississippi program history in receiving yards (2144).