Izaguirre agreed a four-year contract with Scottish Premier League side Celtic on 18 August 2010, subject to receiving a work permit. He signed for a £650,000 fee and was given the number 3 shirt. He made his SPL debut in a 1–0 victory at Motherwell on 29 August, giving a solid performance that drew plaudits from Celtic manager Neil Lennon and Motherwell counterpart Craig Brown. On 19 September, Izaguirre set up Anthony Stokes for the winning goal in a 2–1 victory over Kilmarnock at Rugby Park. On 30 October, he scored his first Celtic goal against St Johnstone, where he intercepted a back pass then flicked the ball over St Johnstone centre back Dave MacKay, before slotting a goal under the goalkeeper. The game ended 3–0 to Celtic, with Izaguirre awarded man of the match for his performance. In Celtic's 3–0 victory over Rangers on 20 February 2011, he set up Gary Hooper's second goal.