The House of Cards star is known for his uncanny impersonations and he channelled his inner Stewart on The Late Show with Stephen Colbert on Wednesday to honour his idol Burnett at the end of her interview with host Colbert.
After noting that one of Burnett's final guests on 1970s variety series The Carol Burnett Show had been her idol Stewart, Colbert introduced Spacey to the stage to pay tribute to his heroine - all while mimicking the late Vertigo legend.
He then recited a poem he had written about Burnett, which began, "Carol Burnett is a wonderful gal, she always makes me laugh somehow.
"All she has to do is put on that silly grin, and I get this funny feeling all over my chin."
Spacey's poem ended with the line, "The drinks are on me all night at the bar, because Carol Burnett is still comedy's greatest star", prompting a touched Burnett to give the actor a big hug as her eyes welled with tears.