The financial terms of the deal were not disclosed, but British media reported that Everton had paid £12m for the 31-year-old central defender.

Everton, who sold defender John Stones to Manchester City on Tuesday for 47.5 million pounds, moved quickly to sign the Welsh club's skipper, who manager Ronald Koeman identified as the man to help plug a defence that shipped 55 league goals last season.

Williams made 36 league appearances for Swansea as they finished 12th last term before he helped Wales get to the semi-finals of a major tournament for the first time.