[4] Together with his brother Gary, he won silver in the Men's lightweight double sculls at the 2016 Summer Olympics,[5][6] and gold in the same discipline at the 2018 World Rowing Championships.

At the 2024 Irish Indoor Rowing Championships, he set a national record on the 2000m ergometer and became the third lightweight man to break six-minutes with a time of 5:58.4.

[17][18] Paul O'Donovan entered UCD in 2012 on an Ad Astra Elite Athlete Scholarship[19][20] and graduated with a BSc in Physiotherapy[21] from University College Dublin in 2017.

Paul and Gary O'Donovan won silver in the lightweight double sculls at the first World Rowing Cup events of the year in Varese, Italy.

[7] O'Donovan was paired with Fintan McCarthy instead of his brother Gary at the 2019 World Rowing Championships held at Linz-Ottensheim in Austria.

The pair won gold in the lightweight double sculls event, which ensured qualification for the Irish team at the 2020 Summer Olympics in Tokyo.

[36] At the 2020 Tokyo Olympics, held in July 2021, the pair set a world's best time of 6:05:33 while winning their semifinal of the lightweight double sculls event.

O'Donovan and McCarthy won their 3rd world title together after winning their title in Belgrade in the Double Sculls also qualifying for the Paris 2024 Olympics O'Donovan and McCarthy once again represented Ireland at the 2024 Summer Olympics, claiming their second successive gold medal in the lightweight double sculls and also becoming the only Irish Olympian to medal at three games.