2018 Mutua Madrid Open

The 2018 Mutua Madrid Open was a professional tennis tournament played on outdoor clay courts at the Park Manzanares in Madrid, Spain from 5–13 May 2018. It was the 17th edition of the event on the ATP World Tour and 10th on the WTA Tour. It was classified as an ATP World Tour Masters 1000 event on the 2018 ATP World Tour and a Premier Mandatory event on the 2018 WTA Tour.

Seeds
The following are the seeded players. Seedings are based on ATP rankings as of 30 April 2018. Rankings and points before are as of 7 May 2018. † The player did not qualify for the tournament in 2017. Accordingly, points for his 18th best result are deducted instead. ‡ The player used an exemption to skip the tournament in 2017. Accordingly, points for his 18th best result are deducted instead.

Withdrawals
The following players would have been seeded, but they withdrew from the event.

Other entrants
The following players received wildcard s into the main draw:
 * 🇪🇸 Pablo Andújar
 * 🇪🇸 Roberto Carballés Baena
 * 🇪🇸 Guillermo García López
 * Stefanos Tsitsipas

The following players received entry from the qualifying draw:
 * Nikoloz Basilashvili
 * 🇷🇴 Marius Copil
 * 🇦🇷 Federico Delbonis
 * 🇷🇺 Evgeny Donskoy
 * 🇦🇷 Nicolás Kicker
 * 🇰🇿 Mikhail Kukushkin
 * 🇷🇸 Dušan Lajović

Withdrawals

 * Before the tournament
 * Marin Čilić → replaced by 🇫🇷 Julien Benneteau
 * Roger Federer → replaced by 🇨🇦 Denis Shapovalov
 * 🇪🇸 David Ferrer → replaced by 🇩🇪 Jan-Lennard Struff
 * 🇷🇸 Filip Krajinović → replaced by 🇷🇺 Daniil Medvedev
 * 🇦🇺 Nick Kyrgios → replaced by 🇩🇪 Mischa Zverev
 * 🇱🇺 Gilles Müller → replaced by 🇮🇹 Paolo Lorenzi
 * 🇬🇧 Andy Murray → replaced by 🇫🇷 Benoît Paire
 * 🇺🇸 Sam Querrey → replaced by 🇺🇸 Jared Donaldson
 * 🇷🇺 Andrey Rublev → replaced by 🇺🇸 Tennys Sandgren
 * 🇫🇷 Jo-Wilfried Tsonga → replaced by 🇺🇸 Ryan Harrison
 * Stan Wawrinka → replaced by 🇩🇪 Peter Gojowczyk

Seeds

 * Rankings are as of April 30, 2018.

Other entrants
The following pairs received wildcards into the doubles main draw:
 * 🇪🇸 David Marrero / 🇪🇸 Fernando Verdasco
 * 🇷🇴 Florin Mergea / 🇨🇦 Daniel Nestor

Retirements

 * 🇺🇸 Bob Bryan (hip injury)

Seeds
The following are the seeded players. Seedings are based on WTA rankings as of 30 April 2018. Rankings and points before are as of 7 May 2018. † The player did not qualify for the tournament in 2017. Accordingly, points for her 16th best result are deducted instead. ‡ The player did not qualify for the tournament in 2017, but was defending points from an ITF Women's Circuit tournament.

Other entrants
The following players received wildcards into the main draw:
 * 🇪🇸 Lara Arruabarrena
 * 🇪🇸 Georgina García Pérez
 * 🇺🇦 Marta Kostyuk
 * Monica Puig
 * 🇪🇸 Sara Sorribes Tormo

The following player received entry using a protected ranking:
 * 🇧🇾 Victoria Azarenka

The following players received entry from the qualifying draw:
 * 🇺🇸 Danielle Collins
 * 🇮🇹 Sara Errani
 * 🇺🇸 Bernarda Pera
 * 🇨🇿 Kristýna Plíšková
 * 🇧🇾 Aryna Sabalenka
 * 🇸🇰 Anna Karolína Schmiedlová
 * 🇪🇸 Sílvia Soler Espinosa
 * 🇷🇺 Natalia Vikhlyantseva

Withdrawals

 * Before the tournament
 * Timea Bacsinszky → replaced by Maria Sakkari
 * 🇺🇸 Catherine Bellis → replaced by 🇨🇿 Kateřina Siniaková
 * 🇩🇪 Angelique Kerber → replaced by Donna Vekić
 * 🇵🇱 Agnieszka Radwańska → replaced by 🇷🇸 Aleksandra Krunić
 * 🇨🇿 Lucie Šafářová → replaced by 🇧🇪 Alison Van Uytvanck
 * 🇩🇪 Laura Siegemund → replaced by 🇰🇿 Zarina Diyas
 * 🇺🇸 Serena Williams → replaced by 🇨🇳 Wang Qiang

Seeds

 * Rankings are as of April 30, 2018.

Other entrants
The following pairs received wildcards into the doubles main draw: The following pairs received entry as alternates:
 * 🇷🇴 Sorana Cîrstea / 🇪🇸 Sara Sorribes Tormo
 * 🇪🇸 Anabel Medina Garrigues / 🇪🇸 Arantxa Parra Santonja
 * 🇺🇸 Christina McHale / 🇨🇳 Peng Shuai
 * 🇷🇺 Anastasia Pavlyuchenkova / 🇺🇦 Olga Savchuk

Withdrawals

 * Before the tournament
 * 🇺🇦 Kateryna Bondarenko (head injury)
 * 🇧🇪 Elise Mertens (gastrointestinal illness)
 * Jeļena Ostapenko (abdominal injury)

Men's singles

 * 🇩🇪 Alexander Zverev def. 🇦🇹 Dominic Thiem, 6–4, 6–4

Women's singles

 * 🇨🇿 Petra Kvitová def. Kiki Bertens, 7–6(8–6), 4–6, 6–3

Men's doubles

 * Nikola Mektić / 🇦🇹 Alexander Peya def. 🇺🇸 Bob Bryan / 🇺🇸 Mike Bryan, 5–3, ret.

Women's doubles

 * 🇷🇺 Ekaterina Makarova / 🇷🇺 Elena Vesnina def. 🇭🇺 Tímea Babos / 🇫🇷 Kristina Mladenovic, 2–6, 6–4, [10–8]