Stuart Slack (25 January 1935 – 5 December 1998) was a racing cyclist from the Isle of Man.

[2] Slack participated in the 1958 British Empire and Commonwealth Games, taking part in the road cycling event.

He finished third in the event, arriving in a five-man group nearly three minutes behind the race winner, Ray Booty[3] winning a Bronze Medal after a photo-finish.

[4][5] In 2011, this result was described as being "against all expectations" and was credited with increasing the popularity of cycling in the Isle of Man.

[10] In 2002, the Isle of Man Post Office issued a set of postage stamps for the 2002 Commonwealth Games in Manchester including a 22 pence stamp depicting the photo-finish of Stuart Slack's third-place finish in the Men's Cycling Road race at the 1958 Empire Games.