Who Is Sophie's Dad In Mamma Mia! - Harry, Bill Or Sam?

It's a question that's obsessed fans of the musical and movie for years — and here we go again. While "Mamma Mia!" tells its audience members many things about its central characters, there's one secret it's never revealed in either the musical, the movie, or its sequel — who fathered Sophie Sheridan (the ever-changing Amanda Seyfried). But here, we'll try to puzzle out that burning query. 

Sophie's potential daddies may consider themselves her father, no matter what any DNA test might reveal, but biologically there can be only one. With that in mind, there are three choices available to the viewer. Using the scant evidence we're given across the "Mamma Mia" universe, it's a difficult but not impossible task to figure out who might have done the deed. 

So who was it? Was it sweet-natured banker Harry Bright (Colin Firth, for whom "Mamma Mia!" just makes the list of his greatest films)? Experienced journeyman sailor and writer Bill Anderson (Stellan Skarsgård)? Or roguish architect Sam Carmichael (Pierce Brosnan)? Here's the strongest evidence for each dad's possible paternity, and the one guy we think really is Sophie's father.

"Mamma Mia!" centers around Sophie, the daughter of single mom Donna Sheridan (the prolific Meryl Streep). Former singer Donna has raised her daughter alone on a friendly, remote Greek island called Kalokairi, running a hotel called the Villa Donna. Sophie has come of age and is ready to marry her own boyfriend, Sky Rymand (Dominic Cooper). Her biggest dream is for her father to walk her down the aisle. The only problem? She has no idea who her biological dad is.

The determined Sophie won't give up, however, and borrows her mom's diary from back around the time she was conceived. The tome narrows down Sophie's possible fathers to Harry, Bill, and Sam. What else can Sophie do but invite all three men to Kalokairi and try to figure out which of the guys is her father — not through DNA, but via behavior? She thinks spending time with all three of them will help her figure things out, and convinces them to keep their presence on the island a secret. 

Slowly but surely, Sophie's plans spin out of control. All three men proudly claim parental duties. Donna panics when confronted by her past, but her unresolved feelings for Sam begin to take center stage. While the mystery behind Sophie's conception is never solved by either musical or movie, there's plenty of evidence that suggests that each of Sophie's potential pops has a fighting chance.

Harry's the true dark horse in the fatherhood race — a very practical man, but with a playful and artistic side that drew Donna in so many years ago. Per "Mamma Mia! Here We Go Again," he was the first of the fathers to dally with Donna, which means that he's first in line on the list of suspects. Sophie and Harry also share a sense of whimsical romanticism. 

But there are a few factors that make Harry's claim on Sophie the weakest of the three fathers. Also as revealed in "Mamma Mia! Here We Go Again," he and Donna only had a one-night stand. While he tries to find her in Greece after their magical evening under the stars, she eludes him and breaks his heart by falling into a whirlwind affair with Bill. 

As we all know, it only takes one sperm and one egg to make a child, but Harry and Donna's lack of repeated interactions means that the likelihood he's Sophie's dad has slim odds.

Bill's strong candidacy for fatherhood stems from one vital fact — his great aunt is the one who gave Donna the money she needed to buy the Villa Donna and stay in Greece. Her name being Sofia is an even bigger hint that Bill might end up being Sophie's father. "Mamma Mia! Here We Go Again" reveals that Aunt Sofia gives the money to Donna because she sees her as a kindred spirit and wants her to succeed, but the notion that there's more than meets the eye behind the gesture still lingers.

Besides that lovely note, Sophie also shares a lot of character traits with Bill. She's adventurous, with a wanderlust that is eventually quenched by a trip around the world with Sky. They also both have a way with words and a shared, ribald sense of humor. Bill is the character Sophie is the most like as a person, which also increases the likelihood that they carry the same DNA.

And then there's Sam — the real love of Donna's life, the potential father she spent the most time with, and the one who offers her the biggest emotional rescue during the movie. If there's a sentimental favorite among the string of pops, it's definitely Sam who's the front runner.

Since Donna and Sam spent the longest amount of time together, he has the highest odds of being Sophie's biological dad due to the sheer number of chances he had to be with her in the biblical way. There would be a sentimental "rightness" to him being the father — he's the one who becomes Sophie's stepfather by marriage, and the one who loved Donna the longest. Mainly, we think Sam would be a great choice as her dad just because he loves Sophie and her mother so much. It would put a sugar-sweet bow on an already charming package. 

We are, to be frank, torn by this one, but we can pretty easily narrow the field down to Sam and Bill — sorry, Harry. Bill has a lot of evidence sprinkled throughout the film's narrative to back up the notion that he's Sophie's father, while Sam is a sentimental favorite. Knowing what we know about the situation in the "Mamma Mia!" movie-verse, which of these two guys is really Sophie's pop?

We're going to have to go with Bill. The physical resemblance between him and Sophie, their similar life philosophies, and their personality types strongly hint that he probably has the honor of being her biological dad. But don't be sad if one of the other fathers feels more suited to the task. After all, if one can learn anything from "Mamma Mia!" it's that biology doesn't matter.

While we and fans everywhere definitely have our opinions about who Sophie's dad should be, it turns out the actors have opinions of their own, and their expectations both match and clash with ours.

Amanda Seyfried's feelings line up with our theory. "I always secretly hoped it was Stellan that was really her father — Bill," she told Vanity Fair. "He was the person who seemed the least likely to want to have kids, and I think from realization to acceptance ... there is a scene that was cut [with] a song called 'Name of the Game,' and we sing it together ... I just really loved that moment with him."

Pierce Brosnan, meanwhile, says he knows who the real daddy is but won't divulge the truth. "I think you'll have to wait for the next movie. I think leave that one right there. I know who it is, but I don't want to be a killjoy," he told The Hollywood Reporter. Fans will have to wait and see whether a third entry of the film series comes to fruition; while the movie is reportedly being developed, nothing has been set in concrete yet.