This is the common name thread for actor Michael J. O'Hara / Mike O'Hara / Michael O'Hara
CLT:
"Michael J. O'Hara" is credited in the following 11 titles (40 profiles)
"Mike O'Hara" is credited in the following 4 titles (9 profiles)
"Michael O'Hara" is credited in the following 11 titles (86 profiles)

Michael J. O'Hara (3 confirmed):
The Drop (confirmed by ninso4)
CSI: NY: Season 1 (confirmed by huskersports)
Parks and Recreation: Season 2 (confirmed by ninso4)

Mike O'Hara (1 unconfirmed):
Monk: Season 7

Michael O'Hara (1 confirmed, 1 invalid):
The Drop
The Wolf of Wall Street (confirmed by ninso4)

Several other Michael O’Hara:
1st to Die (as writer/executive producer)
Stuck on You (as actor)
Do the Right Thing (as song writer)
Summer Storm (as screenwriter)
IQ: Subterranea - The Concert (as actor)
Johnny Nitrate (as actor)
Twilight Zone: Rod Serling's Lost Classics (as executive producer)