Dustytoes - the XBox jack is 2.5mm. You could get away with it if you also got an adapter like this:
http://www.amazon.co.uk/gp/product/B000VLLI18 However, the wisdom amidst my nephews is that you'd be better off just going for any Turtlebeach headsets instead.
http://www.amazon.com/s/ref=a9_sc_1?rh=i%3Aelectronics%2Ck%3Aturtle+beach&keywords=turtle+beach&ie=UTF8&qid=1351192716