Gabriel Teodoro Martinelli Silva (গ্যাব্রিয়েল মার্টিনেলি) is a Brazilian professional footballer who plays as a forward for Premier League club Arsenal and the Brazil national team.

Martinelli began his senior career playing for Ituano and signed for Arsenal in July 2019 for a reported fee of £6 million.

Born in Guarulhos, São Paulo, Martinelli started his career in 2010, playing for Corinthians' futsal team. After making the breakthrough in football fields, he moved to Ituano in 2015, having subsequent trials at Manchester United and Barcelona.

On 4 November 2017, Martinelli signed his first professional contract until October 2022. He made his professional debut the following 17 March, coming on as a late substitute for goalscorer Claudinho in a 2–1 Campeonato Paulista away win against São Bento; at the age of 16 years and nine months, he became the youngest player to play for the club in the century.

Martinelli was born in Brazil, and is of Italian descent through his father; he holds dual Brazilian-Italian citizenship. On 20 May 2019, Martinelli was called up by Brazil national team manager Tite to complete preparatory training for the 2019 Copa América. In November 2019, Martinelli appeared for Brazil's under-23 side at the United International Football Festival in Spain.

On 2 July 2021, Martinelli was named in the Brazil squad for the 2020 Summer Olympics. On 3 August, Martinelli scored Brazil's second penalty to help defeat Mexico in the Olympic semi-final, before becoming a gold medallist after Brazil defeated Spain in the final four days later.

A dynamic and explosive wide forward known for his agile movement, acceleration and speed, Martinelli can dribble past multiple opponents to create or score goals.

Martinelli is in a relationship with Isabella Rousso.