A man fatally jumped in front of an F train inside a Midtown subway station Thursday, police said.

The unidentified man, believed to be in his 60s, jumped in front of the southbound train at the 42nd Street-Bryant Park station at around 12:35 p.m., cops said.

A motorman and a witness told cops they saw the man jump, sources said.

Emergency responders pronounced him dead at the scene.