Pappas has been featured doing stand up on AXS TV, TruTV's How To Be a Grown Up, VH1's Best Week Ever, Fox Business, and Good Morning America. He was the first comedian to ever do stand-up comedy on The Tonight Show with Jimmy Fallon; it was a test show and did not air.
Alongside his stand-up comedy, Pappas had previously partnered up with lifelong friend and director Jesse Scaturro to create the production company Ditch Films in the mid 2000s. The comedy production team produced live and filmed comedy. With Ditch Film, Pappas created his popular internet characters Maurica and Mr. Panos, which premiered online in 2010 and 2009, respectively.
Beginning in June 2013, Pappas co-hosted the MSG Network show The Bracket with Chris Distefano. Later in 2013, he began co-anchoring the live primetime news show Fusion Live alongside journalists, Marianna Antonio and Pedro Andrade. Focusing on current events, pop culture and satire, the show was one of the first for the then-new Fusion network. The show was canceled in December 2014. Beginning in Spring 2015, Pappas hosted the AOL Original Series, 2 Point Lead, a sports comedy show.
Pappas first special, part of Comedy Central's The Half Hour series, aired in June 2014. In 2016, he released his comedy album Let Me Be Yannis, which was recorded live in Madison, Wisconsin. The album was awarded Album of the Year for 2016 by SiriusXM Comedy.
In 2019, Yannis released his first hour-long special Blowing the Light on YouTube. It was produced by comedian Andrew Schulz.