Pelova arrives in North London having made 66 appearances for Ajax, scoring 11 goals since joining in 2019 from ADO Den Haag.
"I'm delighted to have signed for Arsenal. I've always admired this club and dreamt of following in the footsteps of some of the great Dutch players who have worn the shirt," Pelova said in a statement.
Pelova has made 31 appearances for the Netherlands and was a key part of their run to the final of the 2019 World Cup, where they lost to the United States. She was also in the squad that reached the quarter-finals of the European Championship last year.
"It's fantastic news that we've signed Victoria. I think she's one of the most exciting young players in the game," Arsenal coach Jonas Eidevall said.
Arsenal are second in the league standings and also in the quarter-finals of the Women's Champions League, the draw for which will take place next month.
