The Romania international will officially join the club on a five-year contract once the transfer window opens for international transfers on 8th June.
The 25-year-old forward made 69 appearances across two seasons for Deportivo, scoring 18 goals.
Manager Chris Hughton said, “We are delighted that Florin has agreed to join us. He is a player that we have tracked for some time, and he will add a new dimension to our attacking options.
“He is a very hard-working player, and has proven his quality at the highest level in Spain, as well as at international level. I am looking forward to working with him next season."