The Colombian centre-back had been linked to Manchester United and Lyon as well as the Toffees this summer. However after the initial loan Southampton will have an obligation to buy the Englishman for £20 million.
Gomes, who won the European Championships with Portugal in 2016, has found regular first-team football hard to come by at the Nou Camp since joining the Catalans in a big-money move from Valencia in 2016.
The report claims that Mina and Gomes have both completed medicals for the club and will be officially confirmed as Everton players shortly.
His season-long loan will cost the English club 2.25 million euros, Barca said in a statement.
'I have watched the Premier League for a long time. It is the best league in the world.
One of Mina's goals in Russian Federation was against Everton's England goalkeeper Jordan Pickford to send a dramatic last 16 tie into extra-time.
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Financial details of the deal were not disclosed, but local media said West Ham had paid about 4 million pounds for the Spaniard. However, the striker then opted to return to Deportivo on loan last season in search of more regular first-team football .
The Brazil winger, a free agent having allowed his contract with Ukraine's champions to expire at the end of last season, signed a four-year contract at Goodison Park. This is a great opportunity for me and I am looking forward to competing here.
"I have spoken a lot to the coach and I know his passion for Everton and determination to be successful".
Mina, 23, only joined Barca six months ago from Palmeiras, but coach Ernesto Valverde has not been convinced by him and the club have chose to take advantage of his increased value following an impressive World Cup.
Gomes has always been a fringe player at Barcelona, despite signing for a fee of £31m plus €20m in add-ons in 2016, with only 46 appearances made in La Liga since joining from Valencia.
Mina and Gomes join former team-mate Lucas Digne at Goodison, following his move £20m move from Barcelona earlier in the window.