The 24-year-old is yet to make a senior appearance for Chelsea, spending loan spells at the likes of Preston North End, Blackburn Rovers, Bristol City and Nottingham Forest.
Kane spent last season with NEC in the Eredivisie and returned to the Netherlands for the first half of this term, where he made 12 appearances for Groningen.
"At 24 he is that little bit older and more experienced after a few loan moves and has played over 100 senior games now. He is quick, mobile and as you would expect from someone who has been at Chelsea he is really good technically," caretaker manager Derek Fazackerley told the club's official website.
Kane, who becomes Oxford's fifth signing of the January window, could make his debut for the club away to Charlton Athletic in League One on Saturday.