Following interest from Celtic, Cha arrived in Glasgow for a medical on 30 June 2010. In an interview regarding the completion of a move to Parkhead, Cha expressed his desire to compete in an Old Firm derby. Cha signed for Celtic pending approval of a work permit. In doing so he joined up with his national team mate Ki Sung-Yeung.
On 28 July 2010 Cha made his Celtic debut in the UEFA Champions League Third qualifying round against Braga, a 3–0 defeat and on 14 August made his SPL debut against Inverness Caledonian Thistle in a 1–0 win over the Highland side. Cha scored his first Celtic goal against St Johnstone in the SPL on 26 December 2010. On 25 March 2012, Cha was sent off in the Old Firm derby, which Celtic lost 3–2.
