2018: Maiden ATP title and top 50 in doubles As a professional, he emerged into the top 100 of the doubles rankings in February 2018. He won his first ATP title six months later at the
Los Cabos Open, a victory that propelled him into the top 50.
2021: Second career title, first Grand Slam mixed doubles final 2021 was the most successful year on the ATP tour in Arevalo's professional doubles career. He reached in the end of March the quarterfinals in the
2021 Miami Open with
Horia Tecău defeating the top seeded pair of Farah/Cabal. With his Dutch partner
Matwé Middelkoop, the pair reached the quarterfinals of the
Australian Open (his second in a row) and the semifinals of the
Italian Open as alternates, defeating home favorites Fognini/Musetti in the round of 16 and 7th seeded Dutch pair Koolhof/Rojer in the quarterfinals. As a result he returned to the top 50 in the doubles rankings at a career-high ranking of World No. 42 on 17 May 2021. Again as an alternate pair with
Fabio Fognini, Arevalo reached the semifinals of the
Cincinnati Open where they were defeated by No. 2 seeded pair Zeballos/Granollers. As a result, he reached a new career-high ranking of world No. 39 on 23 August 2021. At the
Winston-Salem Open, Arévalo won the title partnering
Matwé Middelkoop when they defeated
Ivan Dodig and
Austin Krajicek in the final. This was his first title in over three years and second of his career. As a result he reached a new career-high ranking of World No. 36 on 30 August 2021. At the
US Open, following a first round loss in the
men's doubles draw, Arévalo partnered
Giuliana Olmos in the
mixed doubles draw and reached the final by defeating top seeds
Nicole Melichar-Martinez and
Ivan Dodig en route. They lost to second seeded pair
Desirae Krawczyk and
Joe Salisbury in straight sets. Arevalo became the first player from El Salvador to reach a
Grand Slam final.
2022–23: Historic Major and Masters doubles titles, World No. 5 After wrapping up 2021 with Middelkoop, Arévalo joined with
Jean-Julien Rojer for a new doubles partnership for the 2022 season. Arevalo reached the top 30 on 17 January 2022. With no title wins during the Australian swing, they moved onto the inaugural
Dallas Open in February as the top seeds, where they clinched their first title together as a team without dropping a set after defeating
Lloyd Glasspool and
Harri Heliövaara. The pair carried their momentum into the following week as the top seeds at the
Delray Beach Open and they sealed their second consecutive title together, having dropped just one set in the championship match to
Aleksandr Nedovyesov and
Aisam-ul-Haq Qureshi. Arevalo reached the top 25 on 21 February 2022. Their winning streak extended yet another week as they reached their third consecutive final and their biggest one as a team thus far, the
ATP 500 in
Acapulco, but they were halted in straight sets by
Feliciano López and
Stefanos Tsitsipas. Although the team started off their European clay swing strongly by reaching the semifinals in
Monte Carlo and
Barcelona, they did not make a final. At the
French Open, seeded twelfth, Arévalo and Roger reached their maiden Grand Slam championship match together to vie for their first Major title as a team, defeating 16th seeds
Rohan Bopanna and
Matwé Middelkoop also first time semifinalists. In the final, they faced
Ivan Dodig and
Austin Krajicek, who, after winning the first set in a tiebreak, had three championship points on Rojer's serve in the second set. But after Arévalo and Rojer saved those decisive points and closed the second set in another tiebreak, they went on to convert their first break point opportunity in the third set and continued to hold serve to seal off the match for their third victory of the season. Arévalo's maiden Grand Slam win made him the first player from Central America to become a men's doubles major champion. As a result, he moved onto the top 10 in the rankings on 13 June 2022. The pair won their fourth title as a team at the
2022 Stockholm Open. He reached a new career-high of World No. 5 on 14 November 2022. At the
2023 Canadian Open, the Arévalo and Roger won their seventh title together and first Masters 1000 defeating
Rajeev Ram and
Joe Salisbury.
2024: Consecutive French Open title, ATP Finals runner-up, World No. 1 With new partner
Mate Pavić, Arévalo defeated
Simone Bolelli and
Andrea Vavassori in the final, 7–5, 6–3 to win title at the
2024 French Open. It was Arévalo's second major men's doubles title and Pavić's fourth. Pavić completed a
career Golden Slam with the win, having previously won the three other
Grand Slams and an
Olympic gold medal. At the
2024 Cincinnati Open he won his second Masters title with Mate Pavić, defeating
Alex Michelsen and
Mackenzie McDonald. On 11 November 2024, he became the world No. 1 player in doubles jointly with his partner Mate Pavić. The duo also clinched the year-end
ATP No. 1 doubles team ranking. They reached the final with a straight set defeat over
Harri Heliövaara and
Henry Patten. They lost to the German duo Kevin Krawietz and Tim Pütz in the final.
2025: Sunshine Double champion Marcelo Arévalo and Mate Pavić won the
Indian Wells Masters becoming the first World No. 1 pair to accomplish the feat since
the Bryan Brothers in 2014, defeating
Sebastian Korda and
Jordan Thompson. They won the next Sunshine Double Masters in
Miami and became only the sixth team in history to accomplish the feat. ==World TeamTennis==