Thomas Allason (1790–1852) was an English architect, surveyor and landscaper, noted in particular for his work at Connaught Square and the Ladbroke Estate in Kensington.

The Ladbroke Estate was a substantial estate of land owned by the Ladbroke family in Notting Hill, London, England, in the early 19th century that was gradually developed and turned into housing during the middle years of the century, as London expanded. Characterized by terraces of stuccoed brick houses backing onto large private garden squares, much of the original building remains intact today, and now forms the heart of one of London's most expensive and fashionable neighbourhoods.