Holy-Cross-of-Westgate Church almost certainly started life as a Chapel in a room above the Roman Westgate. About 1380, Archbishop Simon of Sudbury had the Gate replaced by the present Kentish Ragstone structure, probably designed by Henry Yevele, who was responsible for the current Nave of Canterbury Cathedral. To replace the Chapel, Holy Cross was built alongside.

The Church was renovated three times in the Nineteenth Century, reducing the size of the Tower, and the original Font is now at St Mary's, Minster-in-Thanet. Holy Cross was declared redundant in 1973, and reopened by Prince Charles in 1978 as the Guildhall.