Vlašić, 19, is the Blues thirteenth summer signing and quite possibly their last as the summer transfer window comes to a close.
The Croatian attacking midfielder, who can operate anywhere behind the striker, including on the left wing where impressed in both legs of Split’s Europa League tie against Everton in the play-off round of qualifying.
Niksi, as he’s known in his homeland, caused Everton trouble in both games but was particularly impressive during the second leg in Croatia.
The midfielder created four chances as he operated as Hajduk’s main creative outlet.
After possible complications with a work permit, Vlašić’s move hit a snag on Wednesday evening but those hurdles were quickly overcome and the 19-year-old flew to Merseyside late on Wednesday ahead of his medical on Thursday afternoon.
Vlašić excited by Premier League move
With the fee paid for him, Vlašić is likely to join up with Ronald Koeman’s first team squad rather than David Unsworth’s Under-23 team.
Speaking to EvertonFC.com, Vlašić said: “When I heard that Everton were interested in me, I knew straight away I wanted to come here. Whenever someone called my manager or my father, I told them I only wanted to come to Everton.
“The ambition of the Club is to ultimately play in the Champions League and I want to help achieve that goal," he added. "I believe in myself and in this team - I think we can do great things together.”
Koeman comments on the deal
Whilst Koeman is still searching for a forward, he is still delighted to add a talented youngster like Vlašić to his ranks.
The Everton boss told EvertonFC.com: “We are very happy to bring Nikola to the Club as he is one of the big young talents in Europe.”
“He showed that quality when we played Hajduk in the Europa League and he is only 19, so he will develop," he further explained. “Nikola is one of those players who can play a big part in Everton’s future and in what we want to achieve as a club.”