The record low aggregate score for 72 holes at The Open is 264. Henrik Stenson set the mark at the 2016 championship at Royal Troon in Scotland.
Stenson's four-round card was 68, 65, 68 and 63, producing a total of 264, or 20 under par. He defeated Phil Mickelson by three strokes in one of the most celebrated final-round duels in Open history. Mickelson also broke the previous scoring record, finishing with 267.
The record is an aggregate score, meaning the total number of strokes over four rounds. It is different from the lowest score in a single round: Branden Grace shot 62 at Royal Birkdale in 2017, the first 62 in men's major-championship history at the time.
Stenson's 264 also became the first 72-hole score below 265 in the championship's history. Although later Opens have produced exceptionally low totals, no player has surpassed that mark in the record books covered by the cited championship data.