The 20-year-old moves from Eredivisie side Vitesse Arnhem for an undisclosed fee and has penned a five-year deal at Stamford Bridge.
Van Ginkel came through the youth system at Vitesse and made his international debut as a substitute in a goalless draw against Germany in November.
"I'm very happy to be here at such a nice club with great players," he told www.chelseafc.com. "I am really happy, the stadium is good and the training ground is fantastic.
"I know about all the players and will meet them on Monday.
"I expect a lot, I've watched matches and it's really nice to be here."
Van Ginkel made his first-team debut for Vitesse aged just 17 and made 100 appearances in total, scoring 22 goals.
His 11 goals last season helped earn him the Dutch Talent of the Year Award for the best under-21 player in Holland and also helped him earn international recognition.
Van Ginkel also featured three times for Holland's Under-21s in the recent European Championship, registering two assists as the Jong Oranje made it to the semi-finals.
He becomes Jose Mourinho's second summer signing following the arrival of Andre Schurrle from Bayer Leverkusen.