The Revolution musician claimed three gongs - 'Song of the Year', 'Video of the Year' and 'Single Record of the Year' - for 'The House That Built Me'. She also triumphed in the 'Top Female Vocalist of the Year' category, beating Taylor Swift, Carrie Underwood, Lee Ann Womack and telecast co-host Reba McEntire.
However, Lambert was beaten in the 'Entertainer of the Year' award category by Swift. Accepting the award, the Fearless singer said: "This is the first time that I've ever won this and I'm losing my mind! The fact that this is from the fans makes it so beautiful, thank you so much to the fans and anyone who voted."
Swift, who has just returned from a series of live shows in Europe and Asia, added: "Thanks for not forgetting about me... you are the best thing that has ever happened to me ever, thanks so much!"
Brad Paisley won the award for 'Top Male Vocalist of the Year'. The musician, who has now been honoured 14 times by the ACM, said: "I am honestly shocked, I really am, this is way too many of these [awards] for me! I'm so thankful to the fans of country music for giving me this shot.
"I am so proud of the other nominees, I'm friends with all of you, I don't even want to know how close the voting was on this!"
Paisley went on to thank the voting academy, his team, his wife and family and his dog Holler before leaving the stage.
Multiple Grammy winners Lady Antebellum claimed the prizes for 'Top Vocal Group of the Year' and 'Album of the Year' for Need You Now. Sugarland won the award for 'Best Vocal Duo' and The Band Perry took the prize for 'Top New Vocal Duo or Group of the Year'.
The ceremony featured a duet from American Idol judge Steven Tyler and former winner Carrie Underwood on Aerosmith's 'Walk This Way'. Brad Paisley was joined by members of Alabama on a rendition of 'Old Alabama'.
Darius Rucker was joined by students from the ACM Living Lives programme for a rendition of 'Music From The Heart', James Taylor appeared with the Zac Brown Band, and Rihanna duetted with Sugarland's Jennifer Nettles on a rendition of the Loud singer's new record 'California King Bed'.
Watch Steven Tyler and Carrie Underwood's duet of 'Walk This Way' below:
> In Full: ACM Awards 2011 - The Winners