Gilbert Heathcote-Drummond-Willoughby, 2nd Earl of Ancaster GCVO JP DL (29 July 1867 – 19 September 1951), known as Lord Willoughby de Eresby from 1892 to 1910, was a British Conservative politician.
Ancaster was the eldest son of Gilbert Henry Heathcote-Drummond-Willoughby, 1st Earl of Ancaster, and Lady Evelyn Elizabeth Gordon, daughter of Charles Gordon, 10th Marquess of Huntly. He was born in London and educated at Lambrook preparatory school and at Eton, where he was editor of the Eton College Chronicle and president of the Eton Society. He then attended Trinity College, Cambridge.
In 1894, he was elected to Parliament for the Horncastle Division of Lincolnshire, a seat he held until shortly after the December 1910 general election, when he succeeded his father as second Earl of Ancaster and entered the House of Lords. Ancaster later held office as Parliamentary Secretary to the Ministry of Agriculture and Fisheries under David Lloyd George from 1921 to 1922 and under Andrew Bonar Law and Stanley Baldwin from 1922 to 1924.