This was the first edition of the tournament.
Pablo Cuevas was the two-time defending champion and successfully defended his title, defeating Albert Ramos Viñolas in the final, 6–7(3–7), 6–4, 6–4.
Two-time defending champion Rafael Nadal defeated Stefanos Tsitsipas in the final, 6–2, 6–1 to win the singles tennis title at the 2018 Barcelona Open. With the win, 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 Tour final.
Alessandro Giannessi was the defending champion but chose not to defend his title.
Cristian Garín was the defending champion but chose not to defend his title.
Guido Andreozzi was the defending champion but chose not to defend his title.
Guido Pella was the defending champion but chose not to defend his title.
This article displays the qualifying draw for men's singles at the 2020 Australian Open.
Laslo Đere was the defending champion, but withdrew with an abdominal injury before the tournament began.
The 2020 Forte Village Sardegna Open was an ATP tournament organised for male professional tennis players, held in Sardinia, Italy, in mid-October 2020 on outdoor clay courts. It was primarily organised due to the cancellation of many tournaments during the 2020 season, because of the ongoing COVID-19 pandemic. It was the first edition of the tournament, and it took place in Pula, Italy, from October 12 through 18, 2020.
Pablo Andújar was the defending champion but chose not to defend his title.
This article displays the qualifying draw for men's singles at the 2021 Australian Open.
Diego Schwartzman defeated Francisco Cerúndolo in the final, 6–1, 6–2 to win the men's singles tennis title at the 2021 Argentina Open.
Lorenzo Sonego defeated defending champion Laslo Đere in the final, 2–6, 7–6(7–5), 6–4 to win the men's singles title at the 2021 Sardegna Open. With the victory, Sonego became the first Italian in 15 years to capture an ATP Tour title on home soil.
This was the first edition of the tournament, primarily created due to the one-week delay of the 2021 French Open.
The 2021 French Open – Men's Singles Qualifying is a series of tennis matches that takes place from 24 May to 28 May 2021 to determine the sixteen qualifiers into the main draw of the 2021 French Open – Men's singles, and, if necessary, the lucky losers.
Andrey Rublev was the defending champion, but chose to not defend his title as he and other Russian Olympic athletes were sent to Yuzhno-Sakhalinsk for training sessions.
Miomir Kecmanović was the defending champion, but chose to compete at the Summer Olympics instead.
Facundo Mena was the defending champion but chose not to defend his title.
The 2023 Australian Open – Men's singles qualifying was a series of tennis matches that took place from 9 to 12 January 2023 to determine the sixteen qualifiers into the main draw of the men's singles tournament, and, if necessary, the lucky losers.
Laslo Đere 
Marco Cecchinato 
