In 1795 Richard Watt, a Liverpool merchant who had made his fortune from the sugar plantations of Jamaica, bought the house and 2,400 acre estate for £73,500. He never took up residence there and died without issue in 1796, bequeathing Speke to his great nephew, another Richard who was only ten years old. His coming-of-age in 1807, followed by his marriage to Hannah Burns the following year, prompted substantial refurbishment at Speke.

Although Watt's son lived briefly at Speke before his early death, it was not until his son, the last Richard Watt carried out a major programme of restoration work. The house was then leased to Frederick Leyland, a shipping magnate and patron of the arts, who was responsible for carrying out further restoration work on the ground floor rooms in 1867-78.

Adelaide Watt came of age in 1878 and moved to Speke, taking a keen interest in the estate and in her tenants. Her devotion to the house was reflected in an extraordinary bequest on her death in 1921, when three descendants of the Norris family were named in her will as trustees who could enjoy the house for 21 years.

Development pressures from Liverpool induced Miss Watt to seek more permanent protection, and a second provision allowed for the house to pass to the National Trust, which became the owner in 1943. However, between the wars the trustees sold all but the drive and 27 acres of garden, Chapel Farm becoming the site of Liverpool aerodrome and the farm buildings its first terminal. To protect and enhance Speke's setting, the Trust has bought Stockton's Wood and some adjoining farmland.