The cast of HBO's Prohibition-era drama were rewarded with an ensemble award, while the show's star Steve Buscemi was presented with the gong for 'Outstanding Performance By A Male Actor in A Drama Series' in recognition of his role as Nucky Thompson.
> 'The Help' wins three Screen Actors Guild movie awards
Buscemi used his speech to salute his co-stars and also jokingly thanked Tina Fey - who presented him with the award - for stealing his red wine from the podium and drinking it.
30 Rock star Alec Baldwin beat Ty Burrell and Eric Stonestreet of Modern Family, former Office star Steve Carell and Two and a Half Men's Jon Cryer to win the award for 'Outstanding Performance By A Male Actor in A Comedy Series'.
He paid tribute to writers including Tina Fey and Robert Carlock in his speech, saying that the NBC sitcom has "the greatest writing", and also mentioned the SAG Foundation's literacy initiative Book Pals.
Kate Winslet was honoured for her role in HBO miniseries Mildred Pierce, adding to the Primetime Emmy award and Golden Globe which she has already won for her performance.
The actress was not present on the night to pick up her trophy, which was accepted on her behalf by Damages star Glenn Close.
Betty White was recognised for her role in Hot in Cleveland, saying: "Oh my dears, my dears, my… I don't think they can read. I think they made a terrible mistake."
She went on to praise co-stars Valerie Bertinelli, Jane Leeves and Wendie Malick, adding that her nomination was for all four of them.
"I'm not gonna let them keep this, but I'll let them see it," she concluded.
American Horror Story's Jessica Lange, the cast of Modern Family and Paul Giamatti were also honoured at Sunday's (January 29) ceremony, while Mary Tyler Moore was presented with a Lifetime Achievement Award.
Watch Alec Baldwin's Screen Actors Guild acceptance speech below:
Outstanding Performance By An Ensemble In A Drama Series
Boardwalk Empire - WINNER!
Game of Thrones
The Good Wife
Outstanding Performance By An Ensemble In A Comedy Series
The Big Bang Theory
Modern Family - WINNER!
Outstanding Performance By A Male Actor In A Drama Series
Patrick J Adams (Mike Ross, Suits)
Steve Buscemi (Enoch 'Nucky' Thompson, Boardwalk Empire) - WINNER!
Kyle Chandler (Eric Taylor, Friday Night Lights)
Bryan Cranston (Walter White, Breaking Bad)
Michael C Hall (Dexter Morgan, Dexter)
Outstanding Performance By A Female Actor In A Drama Series
Kathy Bates (Harriet Korn, Harry's Law)
Glenn Close (Patty Hewes, Damages)
Jessica Lange (Constance, American Horror Story) - WINNER!
Julianna Margulies (Alicia Florrick, The Good Wife)
Kyra Sedgwick (Brenda Leigh Johnson, The Closer)
Outstanding Performance By A Male Actor In A Comedy Series
Alec Baldwin (Jack Donaghy, 30 Rock) - WINNER!
Ty Burrell (Phil Dunphy, Modern Family
Steve Carell (Michael Scott, The Office)
Jon Cryer (Alan Harper, Two and a Half Men)
Eric Stonestreet (Cameron Tucker,Modern Family)
Outstanding Performance By A Female Actor In A Comedy Series
Julie Bowen (Claire Dunphy, Modern Family)
Edie Falco (Jackie Peyton, Nurse Jackie)
Tina Fey (Liz Lemon, 30 Rock)
Sofia Vergara (Gloria Pritchett, Modern Family)
Betty White (Elka Ostrovsky, Hot in Cleveland) - WINNER!
Outstanding Performance By A Male Actor In A Television Movie or Miniseries
Laurence Fishburne (Thurgood Marshall, Thurgood)
Paul Giamatti (Ben Bernanke, Too Big to Fail) - WINNER!
Greg Kinnear (President John F Kennedy, The Kennedys)
Guy Pearce (Monty Beragon, Mildred Pierce)
James Woods (Richard Fuld, Too Big to Fail)
Outstanding Performance By A Female Actor In A Television Movie or Miniseries
Diane Lane (Pat Loud, Cinema Verite)
Maggie Smith (Violet, Dowager Countess of Grantham, Downton Abbey)
Emily Watson (Janet Leach, Appropriate Adult)
Betty White (Caroline Thomas, Hallmark Hall of Fame: The Lost Valentine)
Kate Winslet (Mildred Pierce, Mildred Pierce) - WINNER!
Outstanding Performance By A Stunt Ensemble In A Television Series
Game of Thrones - WINNER!
Spartacus: Gods of the Arena