Katy Perry and Bruno Mars are among the myriad performers slated for the “2017 iHeartRadio Music Awards.” Ryan Seacrest hosts the festivities at the Forum in Inglewood. 5 p.m. TBS, TNT, TruTV
Get a crash course in the world’s religions in the new docu-series “Believer with Reza Aslan.” 7 and 10 p.m. CNN
Steve “See? It could happen to anyone” Harvey hosts a new season of the kids talent showcase “Little Big Shots.” 8 p.m. NBC
The fantasy drama “Once Upon a Time” is back with new episodes. 8 p.m. ABC
Masters and Johnson, we presume: Michael Sheen and...