He played college football for the Boise State Broncos and was selected by the Chicago Bears in the seventh round of the 2014 NFL draft.

Leno was a seven-year starter for the Bears, making the 2019 Pro Bowl with them, and also played three seasons with the Washington Football Team / Commanders.

[8] After seven seasons as the Bears starting left tackle, Leno was released on May 3, 2021 after the team selected Teven Jenkins in the second round of the 2021 NFL draft.

[11][12] On December 30, 2023, the Commanders placed Leno on injured reserve due to a calf injury before releasing him on March 1, 2024.

[13][14] On December 16, 2018, after the Bears defeated the Green Bay Packers to win the NFC North division title, Leno proposed to his girlfriend Jennifer Roth at midfield.