Major-General Sir William Lockyer Merewether KCSI CB (6 February 1825 – 4 October 1880) was a Bombay Army officer who served in a number of places including India and Abyssinia.

He was made CB in 1860 and became a secretary to government at Bombay in 1861, served as a political agent and was British Resident at Aden from 1863 to 1867.

[2][3] Merewether played a role as a member of the advance party for the Abyssinia Expedition of 1867–68.

While a colonel, he landed at Mulkutto on the Gulf of Zula 21 October 1867, returning to the settlement at the end of the month, after having first explored along the base of the Ethiopian highlands south until he encountered the Ragolay River, which empties into the Afar Depression, then identified Tekonda Pass as the best entrance to the Ethiopian highlands.

He was knighted in 1868 for his work in negotiating with King Theodore of Abyssinia and for assisting Lord Napier at Bombay in 1867.