Rhett & Link's Buddy System (also known as Buddy System) is an American series produced exclusively for YouTube Premium, created by, written by and starring comedy duo Rhett McLaughlin and Link Neal. The series premiered with episodes one and two being released on October 19, 2016, on Rhett and Link's Good Mythical Morning channel. The season 1 finale was released on November 30, 2016. On November 29, 2017, all episodes of Season 2 were released on the same day. In November 2019, every episode was made free to watch on the Good Mythical Morning YouTube channel.

Season 1 of Buddy System features guest stars Page Kennedy and Leslie Bibb, starring as high school friends of Rhett and Link. After Link's phone is stolen by Infomercial Queen Aimee Brells (Bibb), they undertake a wild range of events battling to return it, while she is also attempting to take over the Good Mythical Morning channel as her own.

Season 2 of Buddy System shows a fictitious version of Rhett and Link in an alternate universe, where Rhett McLaughlin is a professional food tester, and Link Neal is lonely and just fired. They meet for the first time when Rhett is looking for an illegal roommate. They learn how to get on with each other, through the ups and downs, and come out together on the other side.