nvm I don’t know
My daughter just informed me that the theme song for ICarly is sung by Miranda Cosgrove, who plays the title character.
Don’t think it’s been mentioned yet, but ‘Life Goes On’- the theme was ‘Ob-la-di, Ob-la-da’, as sung by the cast.
Chuck Norris sings ALL the theme songs!
And the Drew Carey Show also had another theme song, Cleveland Rocks, also performed by the cast.
“Space Ghost: Coast to Coast”. 
I thought that was The Presidents of the United States doing that, and the cast just lip-synched on camera while running around Cleveland.
It was the PUSA. It’s on their album Pure Frosting. Although on one of the bloopers episodes, the original recording by Ian Hunter was played.
Lawrence Welk…OK, OK, no singing…but sort of my parents’ “The Monkees”. My parents were really a wild pair…They did gut up and dance to some of the songs, though.
Little known fact that the theme to Game of Thrones is hummed by all of the actors that have had their characters killed off on the show.
Ok, I have a real one…
Steve Earle sang the opening theme song of The Wire, "Way Down in the Hole," for the final season and also was an actor on the show (he played Bubbles’ NA sponsor.)
Oh, and speaking of HBO things that Steve Earle was involved in - “Treme’s” theme song is sung by **John Boutté **who appears as himself many times during the series’ run.
Heh, heh, a modern spiritual. I liked how Myron Floren cleared his throat as if he had just taken a few tokes during the commercial.
Well, he does mention Seattle in the lyrics, which one could argue is a story element…
Bill Shatner did the Star Trek theme.
Yeah, it was a rap. Bill has that funky cadence in his speech. 
I believe that Amy Jo Johnson sang the theme to Felicity. She played Julie on the show.
There were apparently lyrics originally written for the theme, but of course not used for the series. Decades later (in '91), Nichelle “Lt. Uhura” Nichols recorded her own rendition.
Also, for the first year of the show Facts of Life, the theme song was sung by a chorus of girls who were ostensibly the students at the school. Charlotte Rae also chimes in as well. (And yes…I do hate myself for knowing this.)
BobLibDem:
I thought it was Katy Perry.
Liv & Maddie…another Disney show theme sung by the lead (Dove Cameron)
Why yes I have a tween daughterI’m pretty sure it’s Zooey. She does have her own band after all. And the girl can sing.