What she she has achieved since, though, working tirelessly to transform the life chances of disadvantaged young people through the Dame Kelly Holmes Trust, is every bit as inspirational. Her gold medals in the 800m and 1500m at the Olympics in Athens left a nation open-mouthed in admiration.
She became the first Brit to win the Olympic middle-distance double in 84 years, over two golden nights for British athletics in the Greek capital, and later admitted her success left her ‘gobsmacked’.
Her achievements won the hearts of a nation, and nobody could argue that a golden end to her career was well-deserved following a succession of near-misses and injury heartbreak in major competition.
Taking up the sport at the age of 12, Kelly joined Tonbridge athletics club and immediately demonstrated her potential, becoming national 1500m champion for her age group within two years.
Remarkably, she didn’t take up the sport full-time until 1997 – just seven years before she completed her famous double.
Combining life on the track with her job in the army for the first five years of her international career - she was awarded the MBE for services to the military - she suffered a stress fracture of the leg at the 1996 Games in Atlanta and an Achilles tendon rupture the following year. Both of those injuries might have signalled the end for someone without her determination - instead they just drove her forward in her quest to take on the best in the world.
A bronze in the 800m at the Sydney Olympics suggested she could do just that, and having arrived in Greece injury-free, Kelly was about to show she could do a whole lot more in the most breathtaking style imaginable.
Coming from last place to first in the final 300m in the 800m, she laid down a marker for the longer event to follow.
What happened next has gone down in history and assured her of her place among the greats of British sport. Brendon Foster described her double as Great Britain’s ‘most glorious moment in athletics history’, while Seb Coe simply described her performance as ‘phenomenal’. Few disagreed.
Kelly retired in December 2005, calling time on her career just months after playing a crucial and leading role in the 2012 Olympics being awarded to her home country.
She transferred the dedication and fierce work ethic that made her a double Olympic champion to setting up and running the Dame Kelly Holmes Trust, which works with disadvantaged young people throughout the UK.
The Trust has now worked with more than 300,000 young people, and 70% of people on its flagship Get on Track programme were in employment, education or training by the time they completed it.
She remains one of Great Britain’s most recognised sporting figures and continues to be an inspiration to young and old following her achievements on the track and her infectious enthusiasm and ability to overcome adversity off it.