Chan Kye Choo was born in Ipoh to Chan Kang Choon. He received English education at St Michael’s Institution, Ipoh. In 1923 he left for London to study law and was called to the English Bar at Middle Temple on 17 November 1927. After four years lived in Wandsworth, London, he returned to Ipoh in 1928, and started to initial as KC Chan. And some time later he was known as KC Chan Sr. and married daughter of Leong Fee in 1932. In 1934, together with Ho Pan Thong son of Ho Yuk Phooi, they established a legal firm, Chan, Ho & Co, premised at 29 Station Road, Ipoh and 40 Kota Road, Taiping. In 1902, he was also a partner in Messrs. C.S. Seng & Co. (Chew Seah Seng). During the Japanese Occupation in Malaya, KC Chan was an official leader of the Chinese community in Perak. He was the President of the Perak Turf Club and Honorary Secretary of the Perak Chinese Amateur Dramatic Association. His son, Colonel KC Chan Jr. was also a lawyer called to the English Bar in Middle Temple and to the Malayan Bar in 1956. One of his prominent cousins was Leong Yew Koh, the first Governor of Malacca who was also a lawyer.