The longest-married living couple that we know of in the UK are Allan and Dorothy McDowell, who got married on 26th September 1941. At 82 years and 138 days, it's a pretty mighty feat. Their daughter is very interested in their record, and it's made me ponder exactly where they rank in the world.
I'd invite people to post the longest marriages they can find here (maybe a minimum of 80 years).
I believe the longest marriage that has reasonable clarity and recognition is that between Herbert and Zelmyra Fisher.
They were married on 13 May 1924 and the marriage lasted 86 years and 290 days, until Herbert’s passing on 27 Feb 2011.
Less reliable suggestions include Karam and Kartari Chand of Bradford, in England, supposedly for 90 years. 291 days.
I do remember this couple and pictures of Mrs Chand who looked remarkably young for the marriage duration suggested. If I recall correctly the children of the marriage were also “rather young” for the supposed marriage duration. I’ll see if I can track that one down in the next 24 hours or so.
Ralph and Dorothy Kohler were married from 1935 to 2021, 86 years, close to the Fishers' record.