The 18-year-old had an impressive campaign with the Dawu-based club in the Ghana Premier League this season as they sit fifth on the log at the end of the first round.
Sani caught the eye of the Spanish club's scouts when they came on tour in Africa and put pen to paper on transfer deadline day but the official announcement was delayed after his medical was postponed due to a reported disagreement on the fee.
“Dreams FC wishes to announce that it has successfully completed the transfer of Abdul Rashid Sani to Girona Futbol Club, S.A.D," a club statement read.
“The transfer is on a one-year loan basis with an option to extend for a further year. This move was done before the transfer deadline in Spain but was made official on Wednesday after the player successfully underwent a mandatory medical,” the statement added.
Rashid's goal against Accra Young Wise last season for Dreams FC was nominated for the Goal of the Year in the maiden edition of Ghana Football Awards.