David Goffin was the defending champion, but withdrew before the tournament began.
This was the first edition of the tournament.
Two-time defending champion Novak Djokovic successfully defended his title, defeating Milos Raonic in the final, 6–2, 6–0, to win the men's singles title at the 2016 Indian Wells Masters. It was his record-equaling fifth Indian Wells title.
Andy Murray was the defending champion, but chose not to participate this year.
Federico Gaio and Stefano Napolitano were the defending champions but only Napolitano chose to defend his title, partnering Salvatore Caruso. Napolitano withdrew in the semifinals.
Juan Martín del Potro defeated the defending champion Roger Federer in the final, 6–4, 6–7(8–10), 7–6(7–2) to win the men's singles tennis title at the 2018 Indian Wells Masters. Del Potro saved three championship points en route to his first ATP Tour Masters 1000 title, having been a runner-up on three previous occasions.
Two-time defending champion Rafael Nadal successfully defended his title, defeating Stefanos Tsitsipas in the final, 6–2, 6–1. By winning the title, Nadal retained the ATP no. 1 singles ranking. It was Nadal's record-extending eleventh Barcelona Open title and his 20th ATP 500 title overall, equaling Roger Federer's record. It was Tsitsipas' maiden ATP final.
Alexander Zverev was the defending champion and successfully defended his title, defeating Philipp Kohlschreiber in the final, 6–3, 6–3.
Nicola Kuhn was the defending champion but lost in the first round to Yannick Hanfmann.
Leonardo Mayer was the defending champion, but lost in the final to Nikoloz Basilashvili, 4–6, 6–0, 5–7. This was Basilashvili's first ATP World Tour title, as well as the first ATP title won by a Georgian player since Alexander Metreveli.
Ivan Dodig and Mate Pavić were the defending champions, but chose not to participate together this year. Dodig played alongside Jean-Julien Rojer, but lost in the quarterfinals to Ben McLachlan and Jan-Lennard Struff. Pavić teamed up with Oliver Marach, but lost in the final to Julio Peralta and Horacio Zeballos, 1–6, 6–4, [6–10].
Novak Djokovic defeated Roger Federer in the final, 6–4, 6–4, to win the men's singles title at the 2018 Cincinnati Masters. With the win, he became the first player to complete the career Golden Masters in singles.
Mirza Bašić was the defending champion but lost in the first round to Martin Kližan.
João Sousa was the defending champion, but lost in the second round to David Goffin.
Marco Cecchinato was the defending champion, but lost in the first round to Aljaž Bedene.
Roberto Carballés Baena was the defending champion but retired in the third round against Jozef Kovalík.
Marco Cecchinato was the defending champion, but lost in the first round to Roberto Carballés Baena.
This was the first edition of the tournament, primarily organised due to the cancellation of many tournaments in 2020, due to the Covid-19 pandemic.
Daniil Medvedev was the defending champion, but chose not to defend his title.
Miomir Kecmanović was the defending champion, but chose to compete at the Summer Olympics instead.
Mirza Bašić 
Marius Copil 
