Harrison began performing stand-up comedy while studying psychology and English at Harvard. (His parents were thrilled.) A summa cum laude graduate, Harrison was the co-founder of the Harvard College Stand-Up Comic Society (or "Harvard College SUCS," as the group's name is cheekily acronymized), the first organization at Harvard dedicated to the performance and appreciation of stand-up comedy and one still popular on campus today.
Moving from Boston to Manhattan (hello Jews!), Harrison quickly became one of the most in-demand comedians in New York, performing in more than 600 shows a year and thus leading both Time Out New York and the NY Daily News to call him "the hardest-working man in comedy." One of Comedy Central's "Comics to Watch," Harrison has also received many awards and honors for his comedy, including the Andy Kaufman Award (2010) for creativity and originality in comedy, the Shorty Award in collaboration with Comedy Central and the New York Comedy Festival for "Best Emerging Comic" (2011), and the Magners Comic Stand-Off (2011). But perhaps the award Harrison is the most proud of is Tannen's Magic Camp "Camper of the Year," which means two things: (1) Harrison went to Magic Camp and (2) Harrison was a virgin until college.
On television, Harrison has been featured on many shows, including NBC's America's Got Talent, NBC's Last Comic Standing, TBS's Conan, Comedy Central's This Week at the Comedy Cellar, AXS.TV’s Gotham Comedy Live, National Geographic Channel's Brain Games, and discovery+'s House Haunters.
When Harrison is not busy getting eliminated from reality competition shows, he's also the star of What's Your Problem? on Facebook Watch and is the creator, writer, and director (phew!) of Recalculating with Harrison Greenbaum, a travel series that has taken Harrison all over the globe and racked up over 2,000,000 views.
Behind the scenes, Harrison was a producer for Primetime: Would You Fall for That? on ABC (which premiered in 2013 to over 3.5 million viewers despite no one Harrison has met having seen it) and a story producer for VH1’s This is HOT 97, as well as the warm-up comic for Katie, Katie Couric's daytime talk show on ABC. Harrison is also currently a writer for Tha God's Honest Truth with Charlamagne Tha God on Comedy Central.
Internationally recognized for his talent, Harrison was the host of The Unbelievables: The World's Greatest Entertainers, which played 22 shows at the Sydney Opera House before commencing a national tour of Australia; was the head writer for Tu Nite con Lorenzo Parro, the first-ever late night show on NBCU/Telemundo; was a featured correspondent on the Japanese television show, Scooper, which was broadcast nationally on Nippon TV; appeared in the documentary, 10 Minutes in America, on France's Canal+; and was a featured act in the Magners Glasgow International Comedy Festival in Scotland. Harrison was also the co-host and featured performer of the official Times Square New Year’s Eve World Wide Webcast in 2010 and 2011, broadcasting live to over 250 million viewers around the globe.
From colleges to comedy clubs, from talk shows to theaters, Harrison is bringing his unique style of comedy to audiences across the country and around the world, proving each night why publications such as the NY Times called him "a favorite young star on the comedy scene" and his mother describes him as "her favorite (and only) son."