Officers were called to reports of the body, next to the Leeds-bound exit slip road at Stourton, at 8.04 am today.
The slip road was closed and a police scene put in place while officers investigated.
Police say there are no suspicious circumstances surrounding the death.
A spokesperson for West Yorkshire Police said: "At 8.04am today police were called to a report of the body of man in an area of trees next to junction 7 of the M621 in Leeds.
"The anti-clockwise exit slip road has been closed and a scene is in place while the circumstances of the death are established."