Dallas S13

E09 Daddy's Dearest@0:46:45
GEORGE O. PETRIE
  ... Harv Smithfield

E25 The Southfork Wedding Jinx
GEORGE O. PETRIE
  ... Harv Smithfield

... did not check the other episodes...

This is the common name thread for actor George O. Petrie / George Petrie
CLT:
"George O. Petrie" is credited in the following 86 titles (180 profiles)
"George Petrie" is credited in the following 125 titles (232 profiles)

George O. Petrie (14 confirmed, 13 unconfirmed):
Planes, Trains & Automobiles (confirmed by T!M)
Baby Boom (confirmed by T!M)
The Blue & the Gray: Season 1 (confirmed by AiAustria)
Knight Rider: Season 4 (confirmed by T!M)
Mad About You: Season 2 (confirmed by T!M)
Mad About You: Season 3 (confirmed by T!M)
Mad About You: Season 4 (confirmed by T!M)
Folks! (confirmed by T!M)
Dallas: Season 3 (confirmed by AiAustria)
Dallas: Season 4
Dallas: Season 5
Dallas: Season 6
Dallas: Season 7
Dallas: Season 8
Dallas: Season 9 (confirmed by AiAustria)
Dallas: Season 10 (confirmed by AiAustria)
Dallas: Season 11
Dallas: Season 12 (confirmed by AiAustria)
Dallas: Season 13 (confirmed by AiAustria)
Dallas: Season 14 (confirmed by AiAustria)
Dallas: J.R. Returns
Dynasty: Season 2
The Drew Carey Show: Season 1 (confirmed by huskersports)
The Twilight Zone/ The New Twilight Zone: Season 1 (episode: Shadow Play)
Night Court: Season 8 (confirmed by huskersports)
Tales from the Darkside: Season 1
Three’s Company: Season 8

George Petrie (9 confirmed, 30 unconfirmed, 10 invalid):
Raid on Entebbe (confirmed by Mad Rockatansky)
Panic in Echo Park (confirmed by Mad Rockatansky)
The Addams Family: Season 1 (episode: Morticia and the Psychiatrist)
The Addams Family: Season 2 (episode: Happy Birthday, Grandma Frump)
The Twilight Zone / The New Twilight Zone: Season 1 (episode: Shadow Play)
The Twilight Zone: Season 4 (episode: In His Image)
The Alfred Hitchcock Hour: Season 1
The Alfred Hitchcock Hour: Season 2
The Andy Griffith Show: Season 2
The Andy Griffith Show: Season 4
Planes, Trains & Automobiles
Murder on Flight 502
At Sword’s Point
Baa Baa Black Sheep: Season 1
Baby Boom
The Blue & the Gray: Season 1
Combat!: Season 1
Dallas: Season 1
Dallas: Season 2
Dallas: Season 9
Dallas: Season 10
Dallas: Season 12
Dallas: Season 13
Dallas: Season 14
The Day After (confirmed by huskersports, AiAustria)
The Munsters: Season 2 (confirmed by AiAustria)
How the West Was Won: Season 3
Gomer Pyle: USMC: Season 2 (confirmed by Nosferatu)
Gypsy (confirmed by ninso4)
Hart to Hart: Season 4 (confirmed by T!M)
Hawaii Five-0: Season 2
Hill Street Blues: Season 3
Ironside: Season 3
Ironside: Season 4 (confirmed by T!M)
The Honeymooners: Season 1
Hud
Knight Rider: Season 4
Leave It to Beaver: Season 6
Little House on the Prairie: Season 8
Maude: Season 5
The Other Side of the Mountain: Part II
Perry Mason: Season 7
Gunsmoke: Season 15
Rawhide: Season 4
Telefon (confirmed by AiAustria)
Wall of Noise
The Wild Wild West: Season 3
Wiseguy: Season 1
Wiseguy: Season 2

I did check Dallas: J.R. Returns (1996) at the starting and end credits but was unable to find him in these credits.
Since I did check the German DVD release, with the title in German, chances are that this (and perhaps several others) credit is removed from the list.

However, I can confirm that George O. Petrie indeed was part of that film.

Whether it is George O. Petrie or George Petrie, this I do not know.