He played college baseball at Stanford University, and was selected by the Cubs in the first round of the 2018 MLB draft.

Hoerner attended Head-Royce School in Oakland, California, where he played soccer, basketball, and baseball.

After the season, he played in the Northwoods League where he hit .304 with two home runs, 31 RBIs, 11 stolen bases, and 12 doubles in 257 at-bats.

[2][6] As a junior in 2018, Hoerner batted .345 with two home runs, 40 RBIs, and 15 stolen bases and was named to the All-Pac-12 team for the second straight year.

[11][12] However, he was placed on the disabled list on July 18 with a strained ligament in his left elbow, and was ruled out for the remainder of the regular season.

[16] He was placed on the injured list on April 27 after being hit on his left wrist, and returned to play in early July.

[26] During the Cubs' Opening Day game against the Milwaukee Brewers on April 7, 2022, Hoerner hit a two-run home run off of reigning NL Cy Young winner Corbin Burnes, the first home run of the 2022 MLB season and Hoerner's first since 2019.

[29] After the Cubs signed free agent shortstop Dansby Swanson in December 2022, it was anticipated that Hoerner would move to second base.

[30] On January 13, 2023, Hoerner agreed to a one-year, $2.525 million contract with the Cubs, avoiding salary arbitration.

[39] Hoerner played in 151 games for the Cubs in 2024, slashing .273/.335/.373 with seven home runs, 48 RBI, and 31 stolen bases.