Jonathon Marshall (born 15 November 2004 in Akron, Ohio) is an English swimmer of American descent.

He holds the SEC meet and Florida Gators team record in the 200y backstroke and 400y medley relay.

[12] In his freshman year at the 2024 Southeastern Conference championships, Marshall won the 100 yard backstroke in 44.12 besting runner up Adam Chaney.

[13] Marshall also won the 200 yard backstroke in a time of 1:36.68, setting the SEC meet record in the event.

His time of 53.03 seconds, behind Oliver Morgan (who won the event in a national record) was fast enough to meet the British consideration criteria for a place at the 2024 Summer Olympics.