The title Earl St Aldwyn, of Coln St Aldwyn in the County of Gloucester, was created in the Peerage of the United Kingdom in 1915 for the 1st Viscount St Aldwyn, who, as Sir Michael Hicks-Beach, 9th Baronet had been a prominent Conservative politician of the late 19th century.

Lord St Aldwyn bears the subsidiary titles of Viscount Saint Aldwyn, of Coln St Aldwyn in the County of Gloucester (1906), and Viscount Quenington, of Quenington in the County of Gloucester (1915), both in the Peerage of the UK, and is an English baronet (1619).

Baronets, of Beverston (1619)

• Sir William Hicks, 1st Baronet (1596-1680
• Sir William Hicks, 2nd Baronet (1629-1703
• Sir Henry Hicks, 3rd Baronet (1666-1755)
• Sir Robert Hicks, 4th Baronet (d. 1768)
• Sir John Baptist Hicks, 5th Baronet (d. 1792)
• Sir Howe Hicks, 6th Baronet (1722-1801)
• Sir Hilliam Hicks, 7th Baronet (1754-1834)
• Sir Michael Hicks Hicks Beach, 8th Baronet (1809-1854)
• Sir Michael Edward Hicks Beach, 9th Baronet (1837-1916) (created Viscount St Aldwyn in 1906)

Viscounts Saint Aldwyn (1906)

• Michael Edward Hicks Beach, 1st Viscount St Aldwyn (1837-1916) (created Earl Saint Aldwyn in 1915)

Earls Saint Aldwyn (1915)

• Michael Edward Hicks Beach, 1st Earl St Aldwyn (1837-1916)
• Michael John Hicks Beach, 2nd Earl St Aldwyn (1912-1992)
• Michael Henry Hicks Beach, 3rd Earl St Aldwyn (b. 1950)