Manchester United announced the signing of the 31-year-old today, who leaves Barcelona after four years in Catalonia.
"I'm really excited to join Manchester United! Not just because of the size of the club and its history, but also to be a part of the journey the club is on with the women's team," Rolfo told the club's website.
Rolfo and Barcelona had agreed to terminate her contract ahead of the UEFA Women's EURO 2025, in which Sweden reached the Quarter-finals, where they were eliminated by eventual winners England.
The left-winger was only able to have a limited impact for the Blagult, as she began the tournament still recovering from a foot injury sustained a month before the EUROs got underway.
She did, however, pass the 100-cap milestone out in Switzerland, and Man Utd will be able to benefit from her wealth of experience at club level, too - she scored 38 goals in 129 appearances for Barcelona, with whom she won four league titles, three Spanish cups and two UEFA Women's Champions Leagues.
Matt Johnson, Director of Women's Football at United, said, “Fridolina is one of the most talented and successful players in the women’s game, both at club and international level. She will add quality and experience to our squad, and the winning mentality of someone with over 20 major honours.
Her signing demonstrates the ambition we have to compete at the highest level in domestic and European competition," he added.
Having previously played for Linkoping, Bayern München and Wolfsburg, Rolfo will experience the WSL for the first time this season.
"The WSL is probably the strongest league in the world right now, so that was a big part of the appeal of coming here, as well as the chance to help the team establish itself in the Champions League," said the Swedish player.
The WSL season begins on 5th September, with Rolfo hoping to be involved for the first time when Manchester United host Leicester City on 7th September.