Estupinan is back in England, where he spent four years on the books of Watford, although he never made a first team appearance for the Hornets, spending time on loan at Granada, Almeria, Mallorca and Osasuna before joining Villarreal on a permanent deal in the summer of 2020.
Estupinan made 74 appearances in total for Villarreal and helped them win the UEFA Europa League in his first season and reach the Champions League semi-finals last term.
The 24-year-old has signed a five-year contract at the AMEX Stadium for an undisclosed fee and will come in as a replacement for Marc Cucurella, who joined Chelsea for a fee in excess of £60m at the start of the season.
Speaking to Brighton's official website on Estupinan's arrival on the South Coast, manager Graham Potter said, "We're excited by what Pervis brings us and he fills a position to which we've been looking to add depth.
"In addition to his international experience, he has played for Villareal in the Champions League and Europa League, as well as gaining plenty of experience in La Liga.
"We will help him to settle here in England, but we're looking forward to working with him and seeing him in action in the Premier League."
Estupinan has won 26 caps for the Ecuador national team.
