Here is a trivia question besides The Andy Griffith Show Happy Days Love American Style and other programming appearance what other show did Ronny Howard played in
The Smith Family with Henry Fonda

For a short while (1959-1960) he appeared on Dennis the Menace. This was the season before TAGS debuted.

Literally just nine days AFTER Ron Howard debuted as Richie on HD, he played the one-shot of Jason's never-before-mentioned terminally ill best friend Seth on "The Waltons". At least Seth and his death's impact on his family DID get mentioned on the show for several years thereafter.

He was also in the Twilight Zone episode "Walking Distance" with Gig Young.

For a short while (1959-1960) he appeared on Dennis the Menace. This was the season before TAGS debuted.

Another show that had a character named Opie (Swanson) as played by Dub Taylor who also appeared in several episodes of TAGS.

He was also in the Twilight Zone episode "Walking Distance" with Gig Young.
WOW! I didn't know he was on the Twilight Zone? Good to know.
https://4-t.imgbox.com/nxeLsBTD.jpg (http://imgbox.com/nxeLsBTD)
https://www.youtube.com/watch?v=GKy8pkeU9hE
He was so cute

For a short while (1959-1960) he appeared on Dennis the Menace. This was the season before TAGS debuted.
Here's a clip from Dennis
https://3-t.imgbox.com/W230cmhg.jpg (http://imgbox.com/W230cmhg)
https://www.youtube.com/watch?v=YMuEZ8VA8p0

He was the narrator for Arrested Development, and even made an onscreen appearance once.

He was on "THE FUGITIVE" once and once he was on "BONANZA" (in the last season which was the 1973-74 season) he was on it in 1973-the year before he started "HAPPY DAYS"

For a short while (1959-1960) he appeared on Dennis the Menace. This was the season before TAGS debuted.
Yeah, as Stuart.

He also appeared in 1 ep. or 2 on the Many Loves of Dobie Gillis.

He also played an under-aged marine in an episode of MASH titled "Sometimes You Hear The Bullet."

If guest appearances count, he briefly appeared as a lawyer in a 2016 episode of the new Odd Couple (in the tribute to Garry Marshall).