I assume from the fact that you’ve posted this on the Traditional Catholicism page that you’re looking for a Traditional church.
Corpus Christi church off Covent Garden, in Central London, does a sung Latin mass on Mondays at 6.30pm.
St James’, Spanish Place, near Marylebone, has a Latin low mass every Sunday at 9.30am, and is also a very impressive looking old gothic church building.
Brompton Oratory is proably the nearest to Kensington & Chelsea and has a low mass at 9.00am.
St Bede’s, Thornton Road, near Balham underground station (some way out of Central London, maybe 45mins on the underground) has a sung Tridentine high mass every Sunday, and a said Tridentine every weekday at 7am. St Bede has a reputation of being the Traditionalists’ unofficial headquarters in London.
More info and a searchable map available at:
latin-mass-society.org/masses/
For a very traditional, very impressive, respectful and proper mass in English according to the New Rite, I’d suggest making your way to Westminster Cathedral near Victoria underground station.