City of London and Westminster South was an electoral division for the purposes of elections to the Greater London Council. The constituency elected one councillor for a four-year term in 1973, 1977 and 1981, with the final term extended for an extra year ahead of the abolition of the Greater London Council.

It was planned to use the same boundaries as the Westminster Parliament constituencies for election of councillors to the Greater London Council (GLC), as had been the practice for elections to the predecessor London County Council, but those that existed in 1965 crossed the Greater London boundary. Until new constituencies could be settled, the 32 London boroughs were used as electoral areas. The City of Westminster was joined with the City of London for this purpose, creating a constituency called Westminster and the City of London. This was used for the Greater London Council elections in 1964, 1967 and 1970.

The new constituencies were settled following the Second Periodic Review of Westminster constituencies and the new electoral division matched the boundaries of the City of London and Westminster South parliamentary constituency.^[1]

It covered much of the innermost part of London, including large parts of Central London and the West End of London. The area was in a long-term period of population decline that was yet to reverse. The electorate reduced from 53,922 in 1973 to 50,119 in 1981. It covered an area of 1,318 hectares (13.18 km²).

The City of London and Westminster South constituency was used for the Greater London Council elections in 1973,^[2] 1977^[3] and 1981.^[4] One councillor was elected at each election using first-past-the-post voting.^[5]