Arthur Gilbert MBE (1921 – 23 October 2015) was an English triathlon competitor who came to notice in 2012 as the world's oldest triathlete.

Gilbert was born in Portsmouth, Hampshire in 1921.^[1][2]

He was a veteran of World War II.^[3] He became a helicopter engineer at Westland Helicopters in Somerset^[4] and used to cycle the 20-mile journey to work.^[5]

Gilbert began running competitively in the 1970s and first competed in a triathlon when he was 64 years old.^[6] He subsequently competed in over 40 multi-event races. His training regime included 50 lengths of his local swimming pool every day, 3 visits to the gym each week and 25 km on a bicycle on Sundays.^[4]

He was awarded the MBE, presented by Prince Charles in 2008, for his charity fundraising.^[4]

Gilbert became Britain's oldest triathlete aged 90, when he completed the Burnham-on-Sea Triathlon in April 2011. His time was 1 hour 20 minutes and nine seconds.^[7] In December 2011 the World Record Academy confirmed the 90-year-old was also the oldest triathlete in the world.^[8]

In May 2012 he was an Olympic torchbearer and jogged the 300-metre stretch through Minehead, Somerset.^[9] As a local celebrity, in July he opened a new care home, Kingfisher Lodge, in nearby Saltford.^[5]

Gilbert competed in his 41st triathlon, the Burnham Sprint Triathlon, in early June 2012. It involved a 500-metre swim, 20 km bike ride and a 5 km run. The swim took 31 minutes and 54 seconds, one hour 11 minutes and 8 seconds for the cycling phase and 59 minutes and 20 seconds for the run.^[3] "It was really tough. As the years go by it gets harder and harder, you do go backwards as you get older," he commented.^[3]

He was fortunate with injuries, his only major problem being a ruptured ankle tendon which he incurred in the mid-1990s.^[2]

After completing another Burnham Triathlon in April 2013, Gilbert suggested it would be his last, preferring to help marshal the Burnham event in 2014.^[10]

Gilbert lived in Burnham-on-Sea, Somerset.^[9] His wife died in 2009 and his son died in the same year, aged only 55. Gilbert said his sports activities helped him through these losses.^[4] He attributed his abilities to a stress-free life, eating bananas and regularly giving blood.^[1]

He died on 23 October 2015 aged 94.^[11][12]