Everton relayed the news:
"For me, it was a no-brainer to come here," said the 27-year-old, per the club's official website. "But now that I’ve come to Everton, the job is not done. I’ve got to work hard and feel my way in. I’m ready and up for the challenge."
Everton manager Ronald Koeman was delighted to get his man. "Yannick is a player who has been a long time on my radar because he’s the type of winger I like—fast, strong and he can play different positions in the forward line," said the Dutchman, per the same source. "He’s a really good signing for the club."
Palace previously rejected an £18 million bid from the Toffees for Bolasie, holding out for closer to £30 million, per the Guardian's Ed Aarons and Ben Fisher.
Bolasie, 27, ends a four-year spell at Palace following his 2012 signing from Bristol City.
He has proved an effective attacker for the Eagles in the Premier League, and he is versatile enough to play anywhere across the attacking line.
Koeman will hope to improve Bolasie's scoring rate, as he has a tendency to squander chances with frustrating regularity.
His return for Palace over the last two seasons in the English top flight has been only nine goals and nine assists in 60 appearances, per WhoScored.com. OptaJoe provided details on the kind of player Everton are getting:
Palace, though, were hardly prolific as a team in front of goal in 2015-16, netting only 39 times in the Premier League, the third-worst return in the division.
Bolasie can be devastating running at defenders with the ball at his feet and could prove an excellent foil for the likes of Ross Barkley and Romelu Lukaku on Merseyside. Still, he must improve his delivery from the flanks and his finishing if he is to make good on his potential and the trust Everton have shown in him.
Everton will be looking to improve on last season's 11th-place finish in the coming season, and Bolasie could play a crucial part as an extra attacker in Koeman's squad.
However, it is something of a gamble for Everton to have signed him given he has not yet proved consistently prolific as either a goalscorer or provider.