The 18-year-old defender had long been linked with a move to Goodison park and has now put pen to paper in a three-year deal with the Premier League club.
Markelo will link up with David Unsworth's Under-23 squad ahead of the 2017-18 Premier League season.
Everton (@Everton) June 19, 2017
“It feels great to be an Everton player," Markelo told the Everton official site. "It’s a nice opportunity for me and I love it here already,
“I heard something about two weeks ago after a tournament I played in and I was very happy. I decided immediately that I wanted to come to Everton.
“I’m looking forward to the season now. I have three years here and I hope to get plenty of playing time, develop as a player and then just keep making steps forward towards the first team.”
Markelo, who had two years remaining on his Volendam contract, made 30 appearances in all competitions at Under-19 level last season.