Chaplin said he was living at the Ritz Hotel during his 1921 London return, supported by The Ritz, the Charlie Chaplin Archive and independent historical reporting.
Charlie Chaplin stayed at The Ritz London during his celebrated return to Britain in September 1921. The evidence includes Chaplin's own statement that he was living at the Ritz, the official Ritz history, Chaplin archival material, contemporary reporting and a hospitality history describing his first-floor suite.
Source conclusion:
The cited sources support a stay at the named hotel.