Ruiter has been a free agent since he was released by Eredivisie side FC Utrecht at the end of last season, and has spent the last couple of weeks on trial with the Black Cats.
The 30-year-old has impressed staff and fans alike with his performances against Bradford City and Scunthorpe United during pre-season, with Simon Grayson seeing fit to offer the keeper a contract and provide fellow new signing Jason Steele with some competition.
Dutchman jumped at the chance to ply his trade in England
Speaking to the club's official website following the announcment of the deal, Ruiter said that he is "very pleased" to have signed for the Wearsiders following his trial period, adding that he is "pleased [he is] finally a Sunderland player."
Ruiter continued by saying that he has had a "great couple of days training with the team" during his trial, in addition to playing "some good games" against League One opposition.
The former Utrecht man praised Sunderland's behind the scenes set-up, saying that "everything was so professional" from "the first moment [he] stepped through the door".
Ruiter admitted that "for me it was always a dream to play in England", adding that if "a club like Sunderland" come calling then "it’s a big chance."
Ruiter has years of Eredivisie experience behind him
The experienced goalkeeper had spent his entire career playing in the Netherlands prior to his move to Wearside, coming through Eerste Divisie side FC Volendam's youth system before making the move to Utrecht in 2012 for a fee of £425,000.
Ruiter spent five seasons with Utrecht and made 157 appearances over the course of his stay, including starts in the UEFA Europa League.
He made 17 appearances for the club last season as they finished 4th in the Eredivisie, prior to suffering a collarbone fracture in December that kept him out of action for most of the campaign.