Oscar Jack Piastri (অস্কার জ্যাক পিয়াস্ট্রি) is an Australian racing driver who competes in Formula One for McLaren. Piastri has won nine Formula One Grands Prix across three seasons.

Born and raised in Melbourne, Piastri began his career in radio-controlled racing before moving into karting aged 10, where he won several regional titles. Graduating to junior formulae in 2016, Piastri won his first championship at the 2019 Formula Renault Eurocup with R-ace GP. He then won both the 2020 FIA Formula 3 and 2021 FIA Formula 2 Championships back-to-back with Prema, becoming the sixth driver in history to win the GP2/Formula 2 title in their rookie season. Piastri is the only driver in history to win Formula Renault, Formula Three, and Formula Two—or equivalent—championships in successive seasons.

Oscar Jack Piastri was born on 6 April 2001 in Melbourne, Victoria, Australia. His father, Chris Piastri, is the founder and owner of HP Tuners, an automotive software company; the company sponsored his junior formulae career with up to A$6.5 million. He served as Piastri's kart mechanic as he contested national championships in Australia. His mother, Nicole Piastri (née MacFadyen), helped raise him in the suburb of Brighton with his three younger sisters—Hattie, Edie, and Mae. He claims Italian, Yugoslavian, and Chinese heritage from his father, as well as Scottish and Irish from his mother. His bedtime stories frequently consisted of automotive books, prompting his father to buy him a radio-controlled car on a business trip when he was six, which he began racing in his backyard.

Outside of motor racing, Piastri is interested in video games—particularly Call of Duty—and cooking. He initially adopted the number 11 in kart racing before a rival started using it, prompting his switch to 81 in national competition, junior formulae, and as his personal driver number in Formula One. His racing helmet also originates from his karting career, utilising base colours of red and blue with fluorescent yellow details—modified from off-the-shelf designs—as well as the flag of Australia. He is a supporter of the Melbourne-based Australian rules football club Richmond. He also plays cricket, where he supports the Australia national team and the Delhi Capitals in the Indian Premier League—the latter after a social media post asking for recommendations of which team to support; he hosted the national team at the McLaren Technology Centre (MTC) following the 2025 ICC World Test Championship final.