The City Council Hall was duly renamed City Hall when King George VI granted city status to Singapore in 1951. After the landslide victory of the People’s Action Party in the 1959 Legislative Assembly General Elections, Lee Kuan Yew was sworn into political office as Singapore’s first Prime Minister with his eight cabinet ministers in the City Hall and formally declared Singapore’s full internal self-governance on the building’s steps. On 3 December 1959, large crowds congregated outside the City Hall to witness the installation of Yusof bin Ishak as Singapore’s first Malayan-born Yang di-Pertuan Negara (‘Head of State’ in Malay). They were also introduced for the first time to the state anthem, Majulah Singapura, state crest, and state flag.

The City Council Hall and Supreme Court the reopened in end-2015 as National Gallery Singapore. This visual arts institution oversees the largest public collection of modern art in Singapore and Southeast Asia.