Arthur Henrique Ramos de Oliveira Melo (born 12 August 1996), known as Arthur or Arthur Melo, is a Brazilian professional footballer who plays as a midfielder for Campeonato Brasileiro Série A club Grêmio, on loan from Serie A club Juventus.

Born in Goiânia, Arthur began his career with Grêmio, and won the Copa Libertadores in 2017. He signed for Barcelona for an initial fee of €31 million in 2018. Arthur joined Italian club Juventus in 2020. He was loaned out to Liverpool in the 2022–23 season, only making one appearance for the club. The following season he was loaned to Fiorentina.

Arthur made his senior debut for Brazil in 2018 after previously being capped by Brazil youth team at under-17 level. He was later part of the squad that won the 2019 Copa América.

Arthur began his career with his hometown club Goiás aged 12. In 2010, after being spotted in a youth tournament, he moved to Grêmio.

In January 2015, following Arthur's impressive performances at the Copa São Paulo de Futebol Júnior, he was promoted from Grêmio's youth team under first-team manager Luiz Felipe Scolari. He unexpectedly started in his first team debut, against Aimoré for the Campeonato Gaúcho. However, he was substituted at half-time by Argentine full-back Matías Rodríguez and made no more senior appearances that season. In 2016, Arthur made his league debut in the last match of the season, a 1–0 home loss against Botafogo, replacing Kaio in the second half.

In 2017, Arthur become a first-team regular after a string of good performances in Primeira Liga and Campeonato Gaúcho. In his Copa Libertadores debut, a 1–1 away draw against Club Guaraní, he was named man-of-the-match after completing 40 passes, with an impressive 100% success rate. His playing style and build earned drawn comparisons with Spanish midfielders Andrés Iniesta and Thiago Alcântara, and attracted interest from European clubs such as Chelsea, Barcelona and Atlético Madrid. In May, Arthur scored his first professional goal, the opener in a 3–1 victory against Fluminense for the Copa do Brasil. In July, he scored his first league goal, the second in a 3–1 away victory against Vitória. In November, was elected by Conmebol the man of match in the second leg of the Copa Libertadores final against Lanús, despite playing only 50 minutes due to an injury.

On 11 March 2018, Barcelona reached an agreement with Grêmio for the transfer of Arthur. The Catalans agreed to pay an initial fee of €31 million plus €9 million in added variables. Arthur signed a six-year contract and was officially announced as a Barça player on 9 July 2018. On 28 July, Arthur scored a goal on his debut against Tottenham Hotspur in a pre-season friendly match.

Arthur Melo made his competitive debut at the 2018 Supercopa de España on 12 August, in which Barcelona won 2–1 over Sevilla. Arthur made his league debut during the first league match of the season, also registering his first assist for the club in a 3–0 win against Alavés. On 31 August, Arthur scored his first goal for Barcelona in 2–2 away draw against Osasuna.