Formed at Deportivo Saprissa in Costa Rica, he moved to Europe in 2013 to play for Club Brugge in Belgium. He spent seven years in Spain's La Liga with Espanyol and Levante, making 111 appearances and scoring four goals.
On 26 January 2016, Duarte agreed a permanent transfer to RCD Espanyol in Spain. The three-year deal cost the club €1.15 million and included a buyout clause of €15 million.[4] He made his debut five days later, coming on at half time and scoring an own goal in a 6–0 loss at Real Madrid.[5] In his next game on 14 February, he scored his only goal in 57 games for the club from Barcelona, opening a 2–1 loss at Valencia CF.[6]
Levante
Duarte moved to fellow La Liga team Levante UD on 1 August 2019, on a two-year deal,[7] though the signing was not registered for three more weeks due to UEFA Financial Fair Play Regulations.[8] His first season in the city of Valencia was marred by serious injuries; on 21 January 2020 he scored his first goal to equalise in a 3–1 loss at Sevilla FC in the last 32 of the Copa del Rey.[9] He missed only three league games in 2020–21, scoring in two minutes to open a 4–3 home win over Real Betis on 29 December.[10]
On 30 April 2021, Duarte added another year to his Levante contract by playing his 26th game of the season, against RC Celta de Vigo.[11] He chose to let his deal expire in May 2022.[12]
Al-Wehda
On 24 June 2022, Duarte joined Saudi Arabian club Al-Wehda.[13]
International career
He was elegible to play for Nicaragua through his mother's family, and Costa Rica through his father's family.
In the team's opening match, he scored his first goal for Los Ticos in a 3–1 defeat of Uruguay.[15] In their second match, the team beat Italy, a 1–0 win that qualified Costa Rica for the knockout stage.[16] Costa Rica completed the group stage unbeaten, recording a second consecutive clean sheet in a 0–0 draw with England in Belo Horizonte.[17] On 29 June, Duarte was sent off for receiving two yellow cards in Costa Rica's round of 16 match against Greece. The team advanced via a penalty shootout to the quarter-finals for the first time in their history, where they lost on penalties to the Netherlands.[18]
In May 2018 he was named in Costa Rica’s 23-man squad for the 2018 FIFA World Cup in Russia.[19]
^Oviedo, Steven; Brenes, Cristian (13 February 2016). "Óscar Duarte marcó su primer gol en España" [Óscar Duarte scored his first goal in Spain]. La Nación (Costa Rica) (in Spanish). Retrieved 31 August 2023.
^"Óscar Duarte renueva en Balaídos" [Óscar Duarte renews in Balaídos]. Mundo Deportivo (in Spanish). 30 April 2021. Retrieved 31 August 2023.
^Sancho de Rosa, Luis (22 May 2022). "Duarte anuncia su marcha del Levante" [Duarte announces his exit from Levante]. Diario AS (in Spanish). Retrieved 31 August 2023.