Mogens Frey Jensen (born 2 July 1941) is a retired Danish amateur cyclist who competed successfully both on the road and on track. He won, along with Gunnar Asmussen, Per Lyngemark and Reno Olsen, a gold medal at the 1968 Summer Olympics in the 4 km team pursuit and finished second individually. However, he is more famous for the way he won stage 9 in the 1970 Tour de France. Here, he defeated his own team captain Joaquim Agostinho. Agostinho was first over the finish line, but was immediately disqualified for putting his hand on Frey's handlebars, thus holding him back in the sprint. It was the only Danish Tour de France stage win until 1983.

Frey also won the individual pursuit event at the 1968 world championships and finished second in 1967 behind Gert Bongers.