'Leave It to Beaver' Star Tony Dow Hospitalized with Pneumonia

Tony Dow, the former child star who starred in one the biggest sitcoms in American history -- "Leave It to Beaver" -- is in the hospital with pneumonia ... TMZ has learned.

Tony was taken to the E.R. Thursday. His wife, Lauren, tells TMZ Tony did not have COVID. In fact, she says he was tested 5 times in the hospital and all results were negative.

There is, however, a COVID connection ... Tony was in the E.R. for 24 hours because there were no beds -- a sign of the times with the Delta variant. Lauren says he's on the mend and his doctors think he could be released within a week. She adds, "On behalf of Tony and myself we thank you for your concern for him."

76-year-old Dow is best known for playing Beaver's older brother, Wally Cleaver, for the show's entire run from '57 to '63 ... having acted in all 234 episodes. Word is ... Tony landed the role with almost no acting experience, even though his mom worked in the biz.

He often played the straight man to the other quirky characters ... like his TV pals, Eddie Haskell or Lumpy, or even his kid brother himself, the Beave -- who was always creating problems somehow.

TD reprised his role as Wally in other 'Beaver' spinoffs and revivals in later years ... always keeping that all-American boy charm about him when playing the character.

He's also starred in shows like "The Greatest Show on Earth,' 'Never Too Young,' -- on which he had a significant role as Chet -- 'Lassie,' 'Mr. Novak,' 'Charles in Charge' and other hit series over the years.

His guest roles are also notable ... having appeared for one-off performances in 'Knight Rider,' "Quincy ME,' 'Murder, She Wrote,' 'The Love Boat,' 'Mod Squad,' 'Emergency!' 'My Three Sons' and more.

He's got quite the directing career too ... his credits include episodes of 'Babylon 5,' 'Harry and the Hendersons (the show), 'Swamp Thing,' 'Coach,' 'Star Trek,' 'Honey, I Shrunk the Kids,' among others. TD's also had a hand in producing a couple TV movies, and has even dabbled in visual effects work too -- including for shows like 'Doctor Who.'

The guy's a noted sculptor as well -- some of his work has been featured in the Louvre. Word is ... he's focused on the latter a lot these days at his Topanga Canyon home.