| Honorific Prefix: | The Right Honourable |
| The Earl of Ancaster | |
| Honorific Suffix: | PC |
| Constituency Mp: | Boston |
| Parliament: | United Kingdom |
| Alongside: | Benjamin Cabbell |
| Term Start: | 1852 |
| Term End: | 1856 |
| Constituency Mp2: | Rutland |
| Parliament2: | United Kingdom |
| Alongside2: | Hon. Gerard Noel |
| Term Start2: | 1856 |
| Term End2: | 1867 |
| Birth Date: | 1830 10, df=y |
| Resting Place: | Church of St. Michael and All Angels, Edenham, Lincolnshire, England |
| Party: | Liberal |
| Father: | Gilbert Heathcote, 1st Baron Aveland |
| Mother: | Clementina Elizabeth Drummond-Willoughby, 24th Baroness Willoughby de Eresby |
Gilbert Henry Heathcote-Drummond-Willoughby, 1st Earl of Ancaster, (1 October 1830 – 24 December 1910), known as 2nd Baron Aveland from 1867 to 1888 and as 25th Baron Willoughby de Eresby from 1888 to 1892, was a British Liberal politician and court official.
Born Gilbert Henry Heathcote, he was the son of Gilbert Heathcote, 1st Baron Aveland, and Clementina Elizabeth Drummond-Willoughby, 24th Baroness Willoughby de Eresby. He was educated at Harrow and Trinity College, Cambridge.
In 1852, Ancaster was elected to the House of Commons for Boston, a seat he held until 1856, and then represented Rutland until he succeeded his father as second Baron Aveland in 1867. In 1872, he assumed by Royal licence the additional surnames of Willoughby and Drummond. He held the office of Deputy Lord Great Chamberlain from 1871 to 1901 and was admitted to the Privy Council in 1880.
In 1888, he succeeded his mother as twenty-fifth Baron Willoughby de Eresby and four years later he was created Earl of Ancaster, in the County of Lincoln. This was a revival of the title held by his maternal ancestors the Dukes of Ancaster and Kesteven.
Lord Ancaster married Lady Evelyn Elizabeth Gordon, daughter of Charles Gordon, 10th Marquess of Huntly, in 1863. Together, they were the parents of ten children:[1]
Lord Ancaster died on 24 December 1910, aged 80, and was succeeded in his titles by his eldest son. His tomb stands alongside that of his uncle in the churchyard at Edenham in Lincolnshire; together the tombs constitute a Grade II listed building.
He owned 31,000 acres.[2]