He played college football for the Illinois Fighting Illini and was selected by the San Francisco 49ers in the first round of the 2012 NFL draft.

Jenkins attended Terry Parker High School in Jacksonville, Florida, where he played on the football team.

[4] As of November 20, 2011, Jenkins's 1,166 receiving yards during the 2011 season ranked second in the Big Ten Conference and 11th among NCAA Division I FBS players.

[8] News of his draft was referenced in that same night's live episode of the NBC sitcom 30 Rock - cast member Cheyenne Jackson performed the show's opening theme song and referenced Jenkins having just been drafted to prove the show was airing live on the west coast.

He appeared in the game but recorded no meaningful statistics as the 49ers fell to the Baltimore Ravens by a score of 34–31.

[13] On August 19, 2013, Jenkins was traded to the Kansas City Chiefs for wide receiver Jon Baldwin.

[14] During a Thursday Night Football game on September 19, 2013, against the Philadelphia Eagles, Jenkins recorded his first career reception, thrown by former 49ers teammate Alex Smith.