Marcus Daniell

Marcus Daniell (born 9 November 1989) is a New Zealand former professional tennis player. He reached his career-high ATP doubles ranking of world No. 34 on 29 January 2018 after reaching the quarterfinals of the Australian Open. He won a bronze medal in the men's doubles at the 2020 Summer Olympics, alongside Michael Venus.

Daniell is a philanthropist and an advocate for effective altruism through his work as the founder of High Impact Athletes and as a member of Giving What We Can.

While mainly playing in futures events, Daniell received a doubles wildcard entry to play in the 2010 Heineken Open, an ATP 250 event in his home country of New Zealand. With new doubles partner, Horia Tecău, they had an improbable run to the finals of the event. The pair first dispatched fellow New Zealanders the Statham brothers, 6–3, 6–2. Daniell and Tecău then won a three set showdown against the third seeded Spaniards Tommy Robredo and Marcel Granollers, 3–6. 7–6(5), 10–8. In the semifinal match Daniell and Tecău faced Johan Brunström and Jean-Julien Rojer who had defeated grand slam winners Lukáš Dlouhý and Leander Paes. Daniell and Tecău prevailed 3–6, 7–6(4), 10–8 to set up a final with Brazilians Marcelo Melo and Bruno Soares. In the championship match, Daniell and Tecău won against the Brazilians 7–5, 6–4, each player winning their first ATP Tour title.

Daniell was to represent New Zealand in both the singles and the doubles, paired with Rubin Statham, at the 2010 Commonwealth Games. However, he had to withdraw due to an ongoing back injury, leaving Statham to compete in the singles alone.

In 2015, Daniell first teamed up with Brazilian Marcelo Demoliner in the ATP Challenger grass series leading up to Wimbledon. They followed their runner-up finish to Ken and Neal Skupski at Surbiton by beating the same opponents a week later in the final at Ilkley.

Daniell won the 2016 Stuttgart Open with Artem Sitak before again teaming up with Demoliner. They reached their first ATP World Tour final at the 2016 Swedish Open.

Daniell competed with Michael Venus at the 2016 Summer Olympics, losing a close first round match to Canadians Daniel Nestor and Vasek Pospisil 6–4, 3–6, 6–7 (6).

In 2017, Daniell and Demoliner reached three ATP World Tour finals, in São Paulo, Lyon and Chengdu, although they were unable to win any of them, and improved their ranking as a team to World No. 15. He achieved his best win when, having had to qualify for the 2017 Swiss Indoors in Basel because Demoliner was playing in Vienna, he and new partner Dominic Inglot beat the top seeds, the world's second-ranked pair of Henri Kontinen and John Peers, in the first round. They eventually lost in the semifinal to Fabrice Martin and Édouard Roger-Vasselin.