The 20-year-old winger spent last season at Everton and had been tipped to return to the Camp Nou first-team fold this season after impressing in the Premier League.
However, Enrique, who was appointed as head coach of the Catalan giants earlier this summer, informed him that he would not be getting regular football this campaign and Deulofeu is now focused on continuing his development at the Europa League champions.
He said at his official presentation: "I was surprised by the decision that the manager took, but I'm going to enjoy this year very much. I want to focus on Sevilla.
"I'm very happy to be here. Luis Enrique told me that I wouldn't be playing, and from the first moment I had my mind set on coming to Sevilla.
"It's a very good club, I have high expectations and hopefully we can have a great year together."
Deulofeu scored four goals in 29 appearances in all competitions for the Toffees last campaign.