Maddie Davidson was born on 8 January 1999 in Christchurch.[2] Her parents enrolled her in trampoline classes after she began jumping on a family friend's backyard trampoline.[3] She has trained at Olympia Gymnastic Sports in Christchurch under coach Alex Nilov since she began trampoline.[4]
Davidson began competing with Alexa Kennedy in synchro competitions in 2018 despite the two living and training on opposite ends of the country.[6] At the 2018 World Cup in Maebashi, the pair finished sixth, and Davidson finished 16th as an individual.[7][8] Then at the 2018 World Championships in Saint Petersburg, Kennedy and Davidson finished 14th in the qualification round.[9] Individually, Davidson qualified into the semifinals where she finished 13th.[10]
Davidson began the 2019 season with a 24th-place finish at the Baku World Cup.[11] At the 2019 World Cup in Minsk, she won the bronze medal in the synchro event with Kennedy.[12] They then finished fourth at the Khabarovsk World Cup.[13] She only competed as an individual at the 2019 World Championships in Tokyo, and she only finished 42nd in the qualification round.[14]
Davidson placed 15th in the qualification round at the 2020 Baku World Cup, making her the third reserve for the final.[15] She finished fourth at the 2021 World Cup in Brescia.[16]
Davidson was selected to compete at the postponed 2020 Olympic Games, which made her the first female trampolinist to represent New Zealand at the Olympic Games.[3][2] Gymnastics New Zealand chief executive Tony Compier remarked that her achievement was a "watershed moment ... one we hope will be inspirational to all young girls and women in our sport."[3] At the Olympics, Davidson finished tenth in the qualification round with a total score of 93.140, which made her the second reserve for the final.[17]
Davidson won the silver medal in the individual event at the 2022 Coimbra World Cup.[18] One week later, she won the bronze medal at the Arosa World Cup.[19] She finished eighth at the 2022 World Championships.[20]
At the 2023 Coimbra World Cup, Davidson finished 12th in the semifinals.[21] She then finished eighth at the Palm Beach World Cup,[22] and she placed 15th in the semifinals at the Varna World Cup.[23] At the 2023 World Championships, she finished 14th in the qualification round and tenth in the semifinals, making her the first reserve for the final.[24][25]
Davidson began the 2024 season by finishing 11th in the semifinals at the Baku World Cup and was the second reserve for the final.[26] She then placed sixth at the Cottbus World Cup.[27] In April, Davidson was selected to represent New Zealand at the 2024 Summer Olympics.[28]
To fund her training, Davidson works as a trampoline coach and also as a personal assistant for an accountant.[6] As of 2024, she is dating fellow trampoline gymnast and Olympic medalist Dylan Schmidt.[29]