Smith played running back for Francis Howell High School in Saint Charles, Missouri.

[2] As a senior in 2014, Smith led the Vikings to an 11–1 record[3] before losing to Rockhurst High School (Kansas City, MO) in the Class 6 semi-final playoff game.

[11] Smith redshirted his freshman season at Northern Illinois University (NIU), to focus on making the switch from running back to linebacker.

In his redshirt sophomore season, Smith led the nation in sacks (14), tackles for loss (29.5), and quarterback pressures (73).

[12][13] This led to him being a 2017 consensus All-American, including first team selections by the Walter Camp Foundation and the Football Writers Association of America.

[16] Smith broke NIU's single season tackles for loss record previously held by Scott Kellar (20).

[17] The Maxwell Football Club named Smith a semi-finalist for the Chuck Bednarik Award, the nation's Most Outstanding Defensive Player of the Year.

[53] On November 15, 2021, Smith was signed to the Las Vegas Raiders practice squad, after a season-ending injury to fullback Alec Ingold.

[54] He was elevated to the active roster on November 21, and played in his first career NFL game, getting snaps on special teams vs the Cincinnati Bengals in week 11.