The 26-year-old signed a national dual contract with the Welsh Rugby Union (WRU) the same month, which means the governing body will fund 60 percent of his pay with the rest being paid by his new Swansea-based club.
"I'm really excited to be joining the Ospreys and starting a new chapter in my career when I return to Wales," North said in a statement. "It was a really positive decision for me to sign a national dual contract with the support and structure it provides.
"I have worked alongside the WRU to finalise my choice of region and I would like to thank everyone involved. I'm really looking forward to becoming an Osprey."
North left Welsh side Scarlets in 2013 to sign for Northampton, and all four regions in Wales were vying for his signature after he announced his intention to return.
"George returning home to Wales is a major positive for Welsh Rugby and for the Ospreys," WRU chief executive Martyn Phillips said. "I know he is really looking forward to next season and making a positive impact on Welsh rugby."
(Reporting by Simon Jennings in Bengaluru; Editing by Christian Radnedge)
