Brighton confirm signing of Argentine left-back Barco from Boca
The 19-year-old, who impressed in Boca's run to the Copa Libertadores final last year, joins on a four-and-a-half year contract for a reported fee of $10 million (£7.87 million).
"We have been aware of Valentin for a long time and have been impressed with the progress he has made at domestic and international level," said Brighton's technical director David Weir.
"He is an exciting prospect, but it’s also important we give him the time as he needs to settle and adapt to new surroundings and the Premier League."
Brighton have become renowned for finding and developing prodigious South American talent.
Ecuador international Moises Caicedo joined Chelsea for a British transfer record £115 million in August, just two-and-a-half years after joining for just £4 million.
Paraguay's Julio Enciso and Argentine Facundo Buonanotte, both 19, have also broke into the Seagulls' first team under Roberto De Zerbi.
