One of the core Olympic sports since ancient times and the largest single sport.
Over the years, men have competed over 52 different events - including tug o' war, standing jump events and cross country - but that number has gradually been reduced to just 24 standard disciplines.
Women contest 23 events - they don't have a 50km road walk on their programme, while the only other variation sees them swap heptathlon (seven disciplines) for men's decathlon (10).
Most recently, the women's 3000m steeplechase was introduced at Beijing 2008.
Historically, USA has dominated the medal count with 332 gold - five times more than the now-defunct Soviet Union and six times more than Great Britain - but placings have been widely spread over 101 different nations.
Finnish distance runner Paavo Nurmi and American sprinter/long jumper Carl Lewis share the record of nine gold medals each, with Jamaican sprinter Usain Bolt and US standing jumper Ray Ewry one behind.
Among women, American sprinter Allyson Felix has six gold to her name.
New Zealand enjoys a proud heritage in Olympic track and field, particularly in the men's 1500m, which it has won three times - Jack Lovelock (Berlin 1936), Peter Snell (Tokyo 1964) and John Walker (1976).
Kiwis have stood atop the dias on seven other occasions - long jumper Yvette Williams (Helsinki 1952), walker Norm Read (Melbourne 1956), Snell over 800m (Rome 1960 & Tokyo), Murray Halberg over 5000m (Rome) and shot putter Valerie Adams (Beijing 2008 & London 2012).
In her fifth Olympics, Dame Val will again lead the NZ contingent, while fellow shot putter Tom Walsh represents our best chance of victory.
Dame Valerie Adams - women's shot put
Connor Bell - men's discus
Lauren Bruce - women's hammer
Camille Buscomb - women's 5000m & 10,000m
Jacko Gill - men's shot put
Malcolm Hicks - men's marathon
Hamish Kerr - men's high jump
Tori Peeters - women's javelin
Julia Ratcliffe - women's hammer
Quentin Rew - men's 50km walk
Zane Robertson - men's marathon
Sam Tanner - men's 1500m
Tom Walsh - men's shot put
Madison-Lee Wesche - women's shot put
Nick Willis - men's 1500m
Five to watch
Armand Duplantis (Sweden)
Swedish pole vaulter Armand Duplantis has broken the world record and is a world silver medallist. Heading to Tokyo, the 21-year old will vie for the medal he has always wanted to win.
"Since I was a kid, I wanted to win an Olympic gold, to be the best pole vaulter in the world," he says.
Brigid Kosgei (Kenya)
Kosgei won her first international marathon in Porto in 2015 and heads to Japan as the favourite for gold. The 27-year-old mother of twins broke the world record in Chicago in 2019 and is a double London marathon winner.
Joshua Cheptegei (Uganda)
The 24-year-old is bidding for the 5000 and 10,000m double in Tokyo. Cheptegei broke the 10,000m world record in Valencia in October, two months after smashing the 5000m mark, which had been in place for 16 years.
Cheptegei knows he faces a huge task to become the eighth man to achieve the Olympic double.
"It would be a mountain to climb," Cheptegei says.
Sha'carri Richardson (United States)
Richardson leads US hopes in the women's 100m, an event they have failed to win since Marion Jones at Sydney 2000, before she had to relinquish the gold medal due to a doping scandal.
Richardson, 21, burst onto the scene two years ago and ran a world-leading time of 10.72s this year, heading into the US trials.
Noah Lyles (United States)
The reigning world 200m champion, Lyles is favourite for gold in Tokyo.
Lyles, who overcame severe asthma as a child, ran a blistering 19.90s to win the 200m at the Golden Games meet in May, about a tenth of a second slower than eight-time Olympic gold medallist Usain Bolt's performance at the 2016 Rio Games.