Zebulon Aiton Lash, KC (September 29, 1846 – January 24, 1920) was a Canadian lawyer, civil servant, and businessman.

In 1872, he became a lecturer at Osgoode Hall Law School.

In 1876, he started working in the Department of Justice in Ottawa as chief clerk.

From September 1, 1876, to May 22, 1882, he was Deputy Minister, succeeding Hewitt Bernard.

He was created a Queen's Counsel in 1879 and was elected a bencher of the Law Society of Upper Canada in 1886.