John Berry Clacy (1810–1880) was a Victorian architect whose practice was centred on Reading and Wokingham in the English county of Berkshire.
[1] John's paternal grandfather and his ancestors were long resident around Barkham in Berkshire.
[2] John was brother-in-law of the Australian travel writer, Ellen Clacy.
Most of Clacy's significant works are Gothic Revival buildings, but the Corn Exchange in Reading that he designed with F. Hawkes is in a style that Nikolaus Pevsner described as "free, debased Renaissance".
[4] In 1868 Clacy and Son's practice was recorded as being in Reading.