(written from a Production point of view)
Born in Rochester, New York, he attended the Ithaca College and earned a degree in Film Production/ Screen Writing in 1990. After he moved to the West Coast in the early '90s he worked as production assistant for several films such as the horror films The Pit and the Pendulum (1991, with Stephen Lee, Mark Margolis, and Jeffrey Combs) and Doctor Mordrid (1992, with Jeffrey Combs, Brian Thompson, and Jeff Austin), in the craft service for the horror film Army of Darkness (1992, with Ian Abercrombie, Patricia Tallman, and Rad Milo), and as special effects mechanic and puppeteer performer in the science fiction comedy Freaked (1992, with William Sadler and Deep Roy), the comedy Prehysteria! (1993), the horror film Puppet Master 4 (1993), the fantasy film Dragonworld (1994), and the science fiction film Pet Shop (1995).
Also in the '90s, O'Hara started to work in front of the camera, mostly in small supporting parts in films including the science fiction film Trancers II (1991, with Jeffrey Combs, Richard Lynch, B.J. Davis, and Chris Doyle), the horror film Puppet Master III: Toulon's Revenge (1991, with Richard Lynch, Ian Abercrombie, Aron Eisenberg, Walter Gotell, and J.D. Walters), Sam Raimi's horror film Army of Darkness (1992), David Lynch's television series Twin Peaks (starring Ray Wise, Wendy Robie, and Mädchen Amick), and the science fiction films Oblivion (1994, with Meg Foster, Julie Newmar, Carel Struycken, George Takei, and Musetta Vander) and its sequel Oblivion II: Backlash (1996, also with Foster, Newmar, Struycken, Takei, and Vander).
As an animator, he worked on the animated and fantasy films Rock-A-Doodle (1991), Thumbelina (1994), The Pagemaster (1994, starring Christopher Lloyd, Ed Begley, Jr., Patrick Stewart, Whoopi Goldberg, and Leonard Nimoy), Cats Don't Dance (1997, with Scott Bakula, John Rhys-Davies, and Rene Auberjonois), The Prince of Egypt (1998, with Patrick Stewart), The Road to El Dorado (2000), Shrek 2 (2004), Enchanted (2007), and Ratatouille (2007, music by Michael Giacchino).
Beside his work in the film industry, O'Hara is also working as animator, writer, producer, and voice actor for video games and worked on Meridian 59 (1996), Delta Force: Land Warriors (2000), Star Wars: Galaxies - Empire Divided (2002), and Frantix (2005).  Currently, O'Hara is working as game designer for The Agency.