Sir John Stirling Ainsworth (30 January 1844 – 24 May 1923) was an English industrialist, banker and Liberal Party politician.

His mother was Mary Laurie, daughter of John Stirling, a Doctor of Divinity from Craigie in East Ayrshire.

He did not win but got the chance to fight the seat again in 1903 at a by-election when the sitting member, Donald Ninian Nicol, died.

At the by-election, which was held on 26 August 1903, Ainsworth won in a straight fight against a Unionist candidate, Mr. C Stewart, by a majority of 1,586 votes.

[9] He commanded the 3rd Volunteer Battalion, the Border Regiment from 1898 to November 1902, and received the honorary rank of colonel as he retired.