Dan Grimaldi (born March 7, 1946) is an American actor and mathematics professor who is known for his roles as twins Philly and Patsy Parisi on the HBO television series The Sopranos, various characters on Law & Order (1991–2001), Don't Go in the House (1979), The Junkman (1983), Men of Respect (1990), and The Yards (2000).^[1]

Grimaldi has a bachelor's degree in mathematics from Fordham University, a master's degree in operations research from New York University, and a PhD in data processing from the City University of New York, and teaches in the Department of Mathematics and Computer Science at Kingsborough Community College in Brooklyn, New York.^[2]

In addition to his role on The Sopranos, he has also had some minor film credits, most notably as mother-fixated pyromaniac Donny Kohler in the 1980 slasher film Don't Go in the House,^[3] and some guest TV appearances, including several episodes on Law & Order as well as appearing in 2011 as Tommy Barrone Sr. in "Moonlighting",^[4] the 9th episode of the 2nd season of the CBS show Blue Bloods. He appeared as an executive in the 2000 film The Yards and Grimaldi also voices "Frank" for the video game Mafia.^{[citation needed]}