Cyril O'Reilly (born 8 June 1958; age 66) is an American actor who played Nahsk in the Star Trek: Deep Space Nine sixth season episode "Who Mourns for Morn?".
He is perhaps best known for his role as Tim Cavanaugh in the 1982 comedy Porky's and in its 1983 sequel, Porky's II: The Next Day. Both films co-starred Wyatt Knight, who has since become O'Reilly's best friend. The first Porky's also starred Kim Cattrall. The first two Porky's films also starred Nancy Parsons.
Prior to Porky's, O'Reilly had appeared in Airplane! (1980, featuring Lloyd Bridges, Jonathan Banks and Gregory Itzin, Kenneth Tobey and Jason Wingreen. Later film credits include Navy SEALs (1990, with Titus Welliver), Philadelphia Experiment II (1993, co-starring Larry Cedar, Gerrit Graham and Marjean Holden), The Cool Surface (1994, with Teri Hatcher and Matt McCoy), The Unspeakable (1996, with Athena Massey), Carnosaur 3: Primal Species (1996, with Stephen Lee), Eruption (1997, with F. Murray Abraham), Midnight Blue (1997, with Dean Stockwell), and Black Dog (1998).
For television, he has appeared in a number of movies along with fellow Trek performers, including Splendor in the Grass (1981, with Merritt Butrick, K Callan and Graham Jarvis), 1987's Carly's Web (with Daphne Ashbrook, K Callan and Gregory Itzin), Baja Oklahoma (1988, with Alice Krige and Anthony Zerbe), A Place to Be Loved (1993, with Sam Anderson and Elizabeth Dennehy), and 2001's Windfall (with Gregg Henry, Jeff Kober, Jeremy Roberts, Daniel Roebuck and Ray Wise). He also had a role in On Wings of Eagles (1986, with Jim Metzler, Lawrence Pressman and Diane Salinger).
For episode television, he has made several appearances on Murder, She Wrote, during which he co-starred with John Arndt, Fionnula Flanagan, Dakin Matthews, Andrew Robinson, Mark Rolston, David Ogden Stiers and William Windom. In 2003, he would appear along with Tim de Zarn, Fionnula Flannagan and W. Morgan Sheppard. Aside from these roles, he has appeared on M*A*S*H (with David Graf and David Ogden Stiers), St. Elsewhere (starring William Daniels, Ed Begley, Jr., Christina Pickles, Ronny Cox, Norman Lloyd, France Nuyen, Jennifer Savidge, Alfre Woodard and Jane Wyatt), Houston Knights (with Harvey Jason and Madlyn Rhue), Hunter (starring Charles Hallahan, with Andreas Katsulas), Matlock (with Michael Ensign and Bruce Gray), The Commish (with Brian Keith), Walker, Texas Ranger, (starring Clarence Gilyard, Jr. and Noble Willingham), Touched by an Angel (with Alan Oppenheimer), ER (with Ed Lauter), and The X-Files (2002, starring Gillian Anderson, with Katy Boyer and George D. Wallace),