Homer once described God as his favorite fictional character, but on other occasions has professed belief (like when he ate the God-waffle off the ceiling).
And then there’s Krusty, who at one point thanked god “even though I never worshipped or believed in him in any way.”
Frank Pembleton on *Homicide * had an ongoing struggle with issues of faith, but I think for most of the series’ run he proclaimed himself an athiest.
There was an episode of *Buffy * (“Conversations with Dead People”) where a recently resurrected vampire asks her if there’s any proof that God exists and she replies, “Nothing solid.” In another episode (“Who Are You”), a group of vampires hold a bunch of parishoners hostage in a church and express their surprise that God doesn’t seem to be there and that being here doesn’t harm them. I found that especially interesting in a show that dealt so heavily with the supernatural. You have countless monsters and evil forces, but the people are pretty much on their own against them. Exactly why crucifixes would burn a vampire was never fully explained; perhaps faith, even if unfounded, is a powerful weapon.
Well, Carl Sagan wrote and hosted Cosmos, but I’ll bet by “on TV” the OP meant “in a fictional show”.
I miss Sagan - he was a huge influence.
There is evidence that none of the main characters in ST:TOS believed in any gods. In The Corbomite Maneuver* the puppet told them that they could pray to their deity or deities before they got destroyed - as far as I can tell they ignored this as if it were absurd, and instead worked out an answer. The wedding in Balance of Terror was clearly non-denominational. Finally, Kirk seems to have made a career of destroying or sneering at self-proclaimed deities.
If there was a chapel on any of the Enterprises, or a chaplain, we never saw it.
I got the impression that Uhura might have been religious. There was that episode with the people worshipping the Sun, and at the end Uhura (I am pretty sure) says, “No, it was The Son (of God).” It’s been so long since I’ve seen that episode, but I somehow thought that she tuned into this when the others hadn’t because she was closer to religion, or a believer herself.
In the really quite good, even excellent ( and therefore quickly cancelled ) teen “dramedy” Freaks and Geeks the female lead Lindsay ( Linda Cardellini ) essentially expresses her loss of faith at one point in the pilot episode, a moment which was key to the development of her character. The DVD commentary for the episode makes the point of her atheism more explicitly and notes how rare it was for TV show character to say in so many words that there is no God.
Highly recommended show for those unfamiliar with it and the DVD set, even the “basic” version, is without a doubt the most lovingly produced TV DVD set I have ever seen, just jammed full of commentaries and extras.
- Tamerlane
I’m pretty sure we did see the chapel. I can’t remember which episode (I’m sure someone will come along to tell us), but a minor crew member who was about to be married was killed in battle. In the final scene, the fiance of the dead crew member is praying in the chapel, and Kirk comes in to console her.
It’s hinted that Uhura is Christian. When monitoring broadcasts from the “Roman Empire” planet, she discovers that they are not sun-worshippers as previously thought, but are in fact referring to the “Son”, as in the son of God. She doesn’t say she’s a Christian, but the tone of her voice makes it seem that she agrees with the belief.
That’s Balance of Terror, as I mentioned. There were no symbols of any religion in the room, and in Blish’s version he mentions that they rearranged a break room for the ceremony, and that Scotty’s wedding gift was to set up a broadcast of the ceremony. In his version, btw, the wedding goes through, which increases the tragedy. At the end she returns to the scene of her almost wedding to grieve. I don’t recall any praying. Anyhow, Kirk performs the purely secular ceremony. If there were a chaplain on board, as there would be for a US Navy ship of similar size, you’d think he or she would be there.
Well, that’s closer. I interpreted it as a reaction to the parallel world discovery. Or perhaps she’s still recovering from having her mind wiped by Nomad. 
Joan’s dad on Joan of Arcadia.
I know there are more, can’t think of them tho.
Brian
A hard-core trekkie will correct me, no doubt, but I think Gene Roddenberry was an atheist, so it seems unlikely he would make any of his characters religious.
IIRC, the episode with the wannabe-Greek god who demanded that the Enterprise crew worship him, Kirk tells him that they have no need of “gods”…and then adds half-heartedly, except the One. Which felt like a network add-on.
So is J. Michael Straczynski, but the female lead in Babylon 5 was a priestess.
“I know I don’t prey to you enough, but if you’re there Superman—save me!”
Babylon 5 had quite a few religious characters who were often portrayed in a positive light. One of the many strengths of the show was its ability to portray all kinds of cultures and personalities without being terribly judgemental or preachy about them.
Continuing with ST, in the Next Gen ep Who Watches the Watchers Picard is mistaken by a “primitive” civilization for an “overseer” (god) and it’s suggested that he set down some “commandments.” He angrily refuses, stating that humanity had gotten over its “superstitions.” This strongly implies that by the time of ST the default mode for humans will be atheism.
Hawkeye Pierce was a self-described agnostic. Some minor MAS*H character described himself as an atheist. Hawkeye said “Really?” The guy replied “Oh, yeah. Swear to God.”
Frank Pembleton had a love/hate relationship with religion, but was shown in the Homicide movie teaching ethics at a Catholic prep school.
Tom Skerrit’s character (the Sherrif) on “Picket Fences” was an atheist. That’s one of the few shows I can think of that took religion serously, and had religious figures that actually belonged to churches.
And, interestingly (considering Joss Whedon is unapologetically strong atheist himself) the show also features Shepherd Book, a serious and credible advocate for faith. There’s a great scene in one episode where River (“she’s craaazy” :D) is tearing pages out of the shepherd’s Bible, saying it’s “broken,” and Book gives her a little speech about being religious that’s one of the more perceptive little nuggets of philosophy I’ve ever seen on television. “You don’t fix faith, River; it fixes you.” And I speak as an atheist myself.
Great show. 
In the pretty old series Good Times when John Amos was written out, the love interest they wrote in for Florida (the Mom) was openly atheist. I can only remember one episode focusing on it though.
I also saw an episode of NYPD Blue where Dennis Franz’s (sp?) alter ego states right out that he doesn’t believe in God. Of course he then backs away with some mubo jumbo about his dead son, thereby murking up the water pretty well.
“That ain’t no Shepard.”