The 24-year-old ends months of speculation over a summer move by recommitting to the Spanish giants for a further three years, with his release clause increasing to €250 million
The Brazil international's release clause is set at €200 million but will increase to €222m next season and then move up to €250m for the remainder of his deal.
Barcelona president Josep Maria Bartomeu revealed at a press conference on Thursday that an agreement was close before the 24-year-old confirmed his intention to stay later in the day.
Neymar, who is set to join the Brazil national team for the Olympic Games next month, has been linked with the likes of Manchester United and Paris Saint-Germain but has now signed a three-year contract extension.
A formal presentation of Neymar's new deal will take place on July 15 ahead of the player's Olympic commitments.
Neymar has scored 85 goals in 141 games since joining Barcelona in 2013, winning eight trophies - including La Liga twice and the Champions League once.