NPR announced this morning that Jon Provost – of “What’s that, Lassie? Timmy’s fallen down the well?” fame is still with us at sixty-four.
Nancy Gates acted in half-a-dozen episodes of Lux Video Theatre from '53 to '57 after making her television debut on Ellery Queen in '52; she also appeared on a number of Ronald-Reagan-hosted episodes of General Electric Theater and Henry-Fonda-hosted episodes of The Star And The Story when she wasn’t busy acting alongside a young Peter Graves on The Pepsi-Cola Playhouse or a young Barbara Billingsley on Four Star Playhouse or a young Peter Lawford on Screen Directors Playhouse and et cetera.
She worked with everyone from Red Skelton to Charles Bronson back in the day.
It would be funny if he ever did say that! 
I’d award him half a point for the title of his memoirs as per that link. 
At the other end of the early-TV-manliness spectrum, Army vet and boxing enthusiast Stuart Whitman had lots of pre-'58 credits on cop shows and cowboy-gunslinger shows and life-in-the-military shows; heck, in the '90s he was still getting work on Walker Texas Ranger and The Adventures Of Brisco County Junior.
Before the Oscar nomination for her '59 work in Imitation of Life, Susan Kohner racked up a healthy number of television credits: in '57, you could see her on Suspicion with Jack Warden, and Wagon Train with Chuck Connors, and Schlitz Playhouse with Bob Cummings – and in '56, Climax! with Agnes Moorehead, and Four Star Playhouse with Charles Boyer, and The Alcoa Hour with Robert Preston – and that’s not counting her pre-'58 work on Cavalcade of America and Matinee Theatre.
Back in '51, Rebecca Welles acted on television in Big Town and Lights Out and Studio One In Hollywood and The Web – and in '57 she was acting on Perry Mason and Gunsmoke and Boots and Saddles and The George Sanders Mystery Theater – and in between, you could see her on Alfred Hitchcock Presents with Thelma Ritter, and on Lux Video Theatre with Jack Lord, and on Danger with Joseph Wiseman, and on Robert Montgomery Presents with James Dean, and et cetera.
The irony, of course, is that Timmy NEVER fell down a well.
You can take Richard “Captain Video” Coogan off your lists
UT~
Again, once he decided to write a Timmy’s In The Well book, all bets were off.
And as for Beam-Me-Up-Scotty lines that didn’t quite make it into a series, note that Skip Homeier played both one of the space hippies and one of the space Nazis on the original-recipe Star Trek after racking up a few dozen pre-'58 television credits in his twenties after making his TV debut as a teen on The Silver Theatre.
I stand (or rathe sit) corrected.
Unless we are sticking solely to Americans:
Bernard Cribbins did a number of 1950s BBC performances,especially David Copperfield… He is primarily known for his voiceover work and his roles in the “Carry On” series of films.
Not certain if anyone has mentioned her, but Kathleen Nolan, best known for her role as Kate McCoy in the 1950s sitcom The Real McCoys is still very much alive. Her last role was a 2008 episode of the former CBS series, Cold Case
Peter Brown, best known for his role as Deputy Johnny McKay in the 1950s-1960s Western series Lawman is still very much with us. He had a number of roles in the later 1950s and his last role was in a 2005 low budget Western.
Sylvia Lewis and Richard Erdman were both regulars on The Ray Bolger Show in '53 and '54, and both worked on The George Burns And Gracie Allen Show, and you could see her on The Colgate Comedy Hour and The Bob Cummings Show when she wasn’t busy on Our Miss Brooks, and you could see him on Science Fiction Theatre and *Schlitz Playhouse * and a bunch of other pre-'58 roles…
…sure as you can still see him now, as the ever-upbeat Leonard on Community.
In '56, he was acting on Crossroads with Coleen Gray, who (a) had already made a dozen other golden-age-of-television appearances in previous years, and who (b) later that month was acting with ten-year-old Kathy Garver, who racked up a dozen of her own pre-'58 TV gigs long before playing Cissy on Family Affair – and she’s still acting too, filming a movie for later this year while another’s in pre-production and a third’s just now been completed.
Barbara Cook made her TV debut in 1950, acting with EG Marshall on Kraft Theatre. And in '51, she did a TV movie with EG Marshall. And in '52, she was performing on Armstrong Circle Theatre with – EG Marshall. I don’t know what that means.
Anyhow, before winning a Tony for her Broadway work in '57, she was a castmember on the Golden Windows soap opera before doing another TV movie; appeared on Producers’ Showcase and Studio One In Hollywood and Alfred Hitchcock Presents; and acted alongside a young Robert Culp, since, well, EG Marshall was busy, I guess.
Ann Robinson of War of the Worlds fame made her TV debut in '52 on Racket Squad; appeared, in '53, on The Web and Lux Video Theatre and Biff Baker, USA; had a recurring role in '54, on Rocky Jones, Space Ranger; and spent '55 and '56 acting on Fury with a twentysomething Peter Graves; her other pre-1957 television credits included work on Mike Hammer, and The Millionaire, and It’s A Great Life, and Passport to Danger, and The Bob Cummings Show, and Studio 57, and Waterfront, plus the pilot episode of Cheyenne with a twentysomething James Garner.
(You could still see her – and Garner, at that – on Cheyenne in '57.)
Joanne Linville – the Romulan Commander who thought she was seducing Spock while a faked-his-death Kirk was stealing the cloaking device – had already acted with William Shatner back in '56, on The Kaiser Aluminum Hour; her other pre-'58 credits included acting with a Peter Falk on Robert Montgomery Presents, long before guesting with him on Columbo; and with Robert Preston on The Alcoa Hour, and with Beverly Garland, on Decoy, and with a whole bunch of actors on episode after episode after episode after episode of Studio One In Hollywood.
(You could still see her on Studio One In Hollywood in '58 – same year she was again acting with Shatner, on The United States Steel Hour. And, come '61, you could even see both of 'em on The Defenders.)
I’ll always remember her as the phoney faith healer on Hawaii Five-O.
Carol Lawrence, the voice of Pearl Pureheat from the 1950s Terrytoons Mighty Mouse animated series is still very much alive. She did voice over work for many years and her last screen credit in 2000 for Sex and the City.
Not certain if anyone has mentioned her,but Naomi Stevens is alive. She is best known for her role in the 1960 Academy Award winning film The Apartment. However, she made many credits in 1950s , starting with the short-lived series, Medic
Also not certain if anyone has mentioned him, but the great James Hong is still very much alive. One of Hollywood’s “go to” Asian character actors his television credits began in 1955 in a series called TV’s Readers Digest and have continued until the upcoming Kung Fu Panda 3 in 2015
Pre-'58, you could see John Wilder everywhere from The Adventures of Rin Tin Tin to The Adventures of Ozzie and Harriet to The Adventures of Jim Bowie: on Lux Video Theatre with a pre-Perry Mason William Hopper; on The Bob Cummings Show, with a pre-Brady Bunch Ann B. Davis; on Circus Boy, with a pre-Monkees Micky Dolenz; on Alfred Hitchcock Presents, with a pre-Beverly Hillbillies Nancy Kulp; and even on Navy Log, with Jack Larson on loan from The Adventures of Superman.
And he also acted on Schlitz Playhouse and Zane Grey Theater and West Point and Telephone Time and This Is The Life before '58. And he was still acting in the '60s, when he started picking up writing credits; and still acting in the '70s, while picking up producing credits and branching out into directing; and he was still working in the '80s and '90s and '00s, because why not?
Gigi Perreau was a child actress in the movies during the '40s, but as a teen in the '50s she made the rounds on Four Star Playhouse with Natalie Wood, and on Climax! with Lon Chaney Jr, and on The Ford Television Theatre with Cesar Romero – all before '58, just like her appearances on The Christophers and Celebrity Playhouse and Lux Video Theatre and Mayor of the Town.
More than thirty years ago, Pat Harrington Jr was partway through his two hundred episodes as Schneider the innuendo-laden handyman on One Day At A Time. And more than thirty years before that, he was making his television debut as a teen in the '40s, on The Ford Theatre Hour with Hume Cronyn and Burgess Meredith.
And pre-'57, while in his twenties, you could see him acting on The Elgin Hour and The Motorola Television Hour and The Plymouth Playhouse – and, in honor of this being March 17th, let me add that you could likewise even see Pat acting with both Patrick Macnee and Patrick O’Neal on The Alcoa Hour in '56.
Back in '51, Don Gordon made his TV debut on the first season of Space Patrol. He then acted on the first season of The Ford Television Theatre with Edmond O’Brien; and the first season of The Kaiser Aluminum Hour, with Paul Newman; and the first season of The Best of Broadway, with Joseph Cotten; all before '57, just like the made-for-television version of Marty that he did with Rod Steiger, or his early work on Studio One In Hollywood, and et cetera.
Decades later – after acting in everything from the first season of The Twilight Zone and the first season of The Outer Limits to the first season of Charlie’s Angels and the first season of The Bionic Woman, plus the first season of Hawaiian Eye and the first season of Knight Rider and the first season of The Blue Angels – you could see him in the first season of Diagnosis Murder with Dick van Dyke (who, back when, had framed and murdered him in an episode of Columbo).
That dude got around.