Ranallo signed a contract with WWE on December 15, 2015, and made his WWE debut as the lead/play-by-play commentator for the SmackDown broadcast team on January 7, 2016, thus being dubbed "The Voice of SmackDown". Ranallo had many commentary partners while calling SmackDown: Jerry Lawler, Byron Saxton, Michael Cole, Tom Phillips, David Otunga, and John "Bradshaw" Layfield. Additionally, Ranallo commentated the Cruiserweight Classic alongside Daniel Bryan; the tournament aired from July 6 to September 14, 2016. Ranallo continued to commentate for the cruiserweights on their weekly WWE 205 Live show which first aired from November 29, 2016. His partners were Corey Graves and Austin Aries. For WWE pay-per-view events, Ranallo was assigned to calling the pre-show of WrestleMania 32 in April 2016, but later commentated on the main cards of several WWE PPVs: the SmackDown and cruiserweight matches on 2016's SummerSlam, Survivor Series and 2017's Royal Rumble, and SmackDown PPVs such as 2016's Backlash, No Mercy, and 2017's Elimination Chamber.
On June 22, 2017, Ranallo announced that he would join NXT as their lead commentator after mutually coming to new terms on a new contract agreement with WWE. On August 31, 2020, Ranallo announced his departure from WWE.