St John's, Smith SquareSt Philip's Cathedral North Front & Cascade Chatsworth HouseHeythrop Park Thomas Archer (1668–1743) was an English Baroque architect.

His buildings are important as the only ones by an English Baroque architect to show evidence of study of contemporary continental, namely Italian, architecture.

One is an entry in the Oxford University register recording his matriculation at Trinity College on 12 June 1686, aged 17; the other, his epitaph, survives in the parish church of Hale, Hampshire.

[6] At Hale, Hampshire, he remodelled St Mary's Church, which also contains his memorial, carved by Sir Henry Cheere to Archer's own design.

In 1709–11 Archer designed a Baroque garden pavilion for Henry Grey, 1st Duke of Kent at Wrest Park, Silsoe, Bedfordshire.