The Colombian global completed a £28.5million switch from Barcelona on Thursday, having been the subject of heavy interest from Manchester United and Lyon.
The Catalan club have included a buy-back clause in the deal with the Toffees.
Mina's was impressive during this summer's World Cup and scored a last minute equaliser against England in their last-16 tie, one of three goals he netted in Russian Federation.
While Bernard was finalising his transfer at Everton's Finch Farm training ground a club delegation led by the director of football, Marcel Brands, concluded deals for Mina and Gomes in Barcelona. 'This is why I am here.
The Premier League club also parted company with Ramiro Funes Mori, Wayne Rooeny and Davy Klaassen among others in the summer transfer window. Six months later and after a good World Cup, they have moved him on for nearly three times what they paid for him, despite him never quite performing during his short stay. This is a great opportunity for me and I am looking forward to competing here. I know about Everton's players and I look forward to being able to play with my new team.
"I chose Everton because of all the things I had heard about Marco Silva and after speaking to him I was happy with what he said to me", he told evertontv.
The Colombian centre-back had reportedly been subject to interest from Manchester United over a permanent move but Everton have swooped in for Mina on the final day of the English transfer window, with the player having his medical in Barcelona in order to push the move through.
Mina joins Everton on a five-year contract for a fee thought to be in the region of £27m, while Gomes jets in on a season-long loan deal.