[1] In September, he made his debut for the Dutch Davis Cup team in the World Group play-offs against the Czech Republic, losing against Tomáš Berdych in straight sets and winning over Jan Hernych after the competition already was decided.

Capping off a good week, he reached the final in doubles with compatriot Rogier Wassen, but lost in straight sets.

In August, Haase for the first time defeated a top-10 player at the Rogers Cup, beating Tomáš Berdych.

Haase made his Grand Slam debut at the US Open as a lucky loser, due to the withdrawal of Mario Ančić.

[5] Robin Haase meant to start the year playing in Chennai, but because of troubles obtaining a visa, he had to withdraw.

[6] In Australia, he lost first-round matches in Sydney and Melbourne, losing first to Alex Bogomolov Jr. and then to Andy Roddick.

[7][8] At the indoor tournament of Zagreb, Haase was seeded seventh and reached the quarterfinals, losing to Lukáš Lacko.

[9] In February, he helped the Dutch Davis Cup team to a 5–0 victory over Finland in World Group I, playing a singles match and partnering in the doubles with Jean-Julien Rojer.

[10] In Rotterdam and Indian Wells, Haase lost again in the first round, this time to Nikolay Davydenko and Pablo Andújar.

In the quarterfinals, playing top seed, Novak Djokovic, who defeated him in straight sets, despite Haase breaking his serve four times.

Robin Haase was the first Dutch player in nine years to reach a Masters Tournament quarterfinals, the last being Martin Verkerk.

In 2013, Robin Haase partnering with fellow Dutch Igor Sijsling reached the finals of the 2013 Australian Open where they lost to the Bryan brothers.

Haase reached the quarterfinals in doubles at the 2017 US Open (tennis) with Matwé Middelkoop and at the 2018 Wimbledon Championships with Robert Lindstedt.

He reached also two ATP 500 doubles finals at the 2019 Hamburg European Open with Koolhof and at the 2022 ABN AMRO World Tennis Tournament with Matwé Middelkoop, winning the latter.

At the 2022 Swiss Open Gstaad he reached the final in doubles with Philipp Oswald,[21] where they lost to Tomislav Brkić and Francisco Cabral.

His singles ranking dropped out of the top 300 on 10 October 2022 but following a semifinal showing at the Challenger in Hamburg, where he lost to Henri Laaksonen, he climbed 35 positions back to No.

He entered the 2023 Adelaide International 2 as a lucky loser replacing Maxime Cressy in the last minute after being an alternate in qualifying, and won his first singles match since February 2021 against Benjamin Bonzi in three tight sets 3–6, 7–6(8), 7–6(3).

At the 2023 Open Sud de France he reached his twentieth doubles final partnering compatriot Middelkoop.

He is capable of producing spectacular shots, such as powerful forehands down the line on the run, à la Sampras, or backhand winners while taking the ball on the rise, his left foot in the air.