There are some streets missing in the 1861 see TNA
https://www.nationalarchives.gov.uk/help-with-your-research/research-guides/census-records/Google AI says
Parts of the 1861 census for London are missing, including:
Parts of the parishes of St Dunstan in the West, St Gregory by St Paul, and St Mary Staining
Parts of the Inner Temple and St Michael-le-Quern
Parts of St Botolph-without-Bishopsgate
The first six pages of the parish of St Bride
Belgravia Sub-district, within St George's Hanover Square District
Parts of Chelsea District
Pieces RG9/145, 219, 407, 601, 903, 1039, 1234, 3388, 4015, 4022, 4131, 4137, 4196, 4291, 4344, 4389, where all parishes are missing