The 22-year-old former Real Madrid midfielder pens a four-year contract with the Basque side after an unsuccessful stint at Valencia, where Seydou Keita takes his place
The injury-plagued former Real Madrid man had been linked with a move away from Mestalla throughout the transfer window, with Premier League side Fulham reported to have been interested in the 22-year-old.
However, Sociedad confirmed the capture of Canales on deadline day, revealing that the former Spain Under-21s international had put pen to paper on a four-year deal with the Basque outfit after passing a medical.
The arrival of Seydou Keita at Valencia allowed Sociedad to make their move for the midfielder and he returns to the north of Spain, where he began his career with Racing Santander before moving to Madrid in August 2010.
Canales will be formally presented to the press on Monday after his new side's Primera Division meeting with Atletico Madrid.