The club announced the signing of the former former Shakhtar Donetsk player just 21 minutes before the 5pm deadline.
Several Premier League sides including West Ham and Chelsea had been in the hunt for the Brazilian winger while AC Milan also expressed an interest.
During negotiations for Mina, Everton were offered Gomes on a season-long loan, the Portugal midfielder having struggled at Barcelona since his €35m (£31.5m) arrival from Valencia two years ago.
Everton have signed André Gomes on loan from Barcelona.
A summer that started with the intention of balancing the books ended with a flourish as Farhad Moshiri, Everton's major shareholder, sanctioned a deal for Mina, which took the club's spending to about...
The fee for Mina, who only joined the Spanish champions in January, could rise by 1.5 million euros and Barcelona have inserted a buy-back clause in the player's contract.
"The manager made me feel confident about playing here".
'They are historically among the four most successful clubs in England and when I found out about the club and what the manager wanted from me, I was happy.
"All those we signed showed me they really want to come".
Everton, who finished eighth in the Premier League last season, have always been viewed as the side most likely to mount a challenge to break into the illustrious top six.