Egremont William Lascelles (26 July 1825 – 27 October 1892) was a British Conservative Party politician.
Lascelles was the son of Henry Lascelles and Lady Louisa Thyme. In 1856, he married Jessie Elizabeth Malcolm — daughter of Neil Malcolm and Harriet Mary Clarke-Jervoise — and they had two children: Marion (died 1938) and Clare (–1883).
In 1847, Lascelles became a lieutenant captain in the Grenadier Guards and in 1852, he became major of the 1st Regiment of West York Militia. He was later also a Deputy Lieutenant.
He was elected MP for Northallerton at a by-election in 1866 but did not seek to retain the seat at the next general election in 1868.