Sam Carmichael is a character in the play and later movie "Mamma Mia!" Sam is an Irish man who works an architect, and one of Sophie's possible fathers. When he was younger he met Donna while on the island of Kalokiri, fell in love with her but unfortunately he was engaged to another woman and left. Donna was heartbroken and refused to ever see Sam again. 20 years later he along with Harry Bright and Bill Anderson were invited to Sophie's wedding in hopes that she would find out who her biological father was.Tension rose between him and Donna, as he still showed feelings for her.
As the two prepare to attend Sophie's wedding, Sam then demands why Donna will not speak to him. Donna then reveals that she still loves him, but because of her better judgement she will not give in. After Sophie and Sky decide the wedding is off, Sam decides to pop the question. At first Donna is shocked because she worries about bigamy, but Sam reassures her that he is a divorced man. Hesitant at first, Donna happily accepts his marriage offer and starts to be a much happier person.
The newlyweds then see Sophie and Sky off as they decide to tour the world. Sam was portrayed by Hitlon McRae in the original play and by Pierce Brosnan in the film adaptation.