Guido Joel Knudson (/ˈɡiːdoʊ kəˈnuːdsən/; born August 5, 1989) is an American former professional baseball pitcher.

Prior to playing professionally, Knudson attended Bonita Vista High School and then the University of California, San Diego.

"[5] On August 20, 2015, the Tigers purchased the contract of Knudson from the Toledo Mud Hens after placing starters Aníbal Sánchez and Daniel Norris on the disabled list.

Prior to being called up by the Tigers, Knudson had a 1–2 record and a 2.52 ERA in 30 appearances with the Mud Hens, allowing 27 hits over 391⁄3 innings, with 21 walks and 40 strikeouts.

In his debut, he pitched one inning, allowing one hit, a home run to Rougned Odor, with two strikeouts and no walks.