Niall Macfarlane Mackenzie (born 19 July 1961) is a Scottish former professional motorcycle road racer.

Mackenzie, who hails from Fankerton, near Denny, Stirlingshire; won the British Superbike Championship three times from 1996 to 1998 with the Rob McElnea-run Yamaha team, and the British 250cc and 350cc titles twice earlier in his career.

He had a long career in the Grand Prix motorcycle racing circuit, debuting in 1984 in the 250cc class.

He moved up to the 500cc class in 1986 on a Suzuki before spells on Honda and Yamaha motorcycles.

[1] His final racing season was the 2000 British Superbike series, although he did a farewell one-off at Knockhill in 2001 and stood in for the injured Yukio Kagayama at Donington Park in 2003.