In 1858 Henry Petty-Fitzmaurice, 3rd Marquess of Lansdowne, one of Petty's descendants, erected a memorial and likeness of Petty in Romsey Abbey. The text on it reads: "A true patriot and a sound philosopher who, by his powerful intellect, his scientific works and indefatigable industry, became a benefactor to his family and an ornament to his country". A monumental slab on the floor of the south choir aisle of the Abbey reads "HERE LAYES SIR WILLIAM PETY". He also erected the Lansdowne Monument on Cherhill Down in Wiltshire.