| Singles | |
|---|---|
| 2018 Fairfield Challenger | |
| Champion |  Bjorn Fratangelo |
| Runner-up |  Alex Bolt |
| Score | 6–4, 6–3 |
Mackenzie McDonald was the defending champion but chose not to defend his title.
Bjorn Fratangelo won the title after defeating Alex Bolt 6–4, 6–3 in the final.
Jordan Thompson (quarterfinals)
Lloyd Harris (quarterfinals) Noah Rubin (second round) Reilly Opelka (first round)
Adrián Menéndez Maceiras (semifinals, retired)
Casper Ruud (semifinals)
Ivo Karlović (first round) Alex Bolt (final)| Semifinals | Final | ||||||||||||
| Bjorn Fratangelo | 6 | 6 | |||||||||||
| 6 | Casper Ruud | 2 | 2 | ||||||||||
| Bjorn Fratangelo | 6 | 6 | |||||||||||
| 8 | Alex Bolt | 4 | 3 | ||||||||||
| 5 | Adrián Menéndez Maceiras | 5 | 6r | ||||||||||
| 8 | Alex Bolt | 7 | 6 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | J Thompson | 77 | 6 | ||||||||||||||||||||||||
 J Clarke | 63 | 1 | 1 | J Thompson | 65 | 6 | 6 | ||||||||||||||||||||
| WC | A Rybakov | 68 | 3 | SE |  M Janvier | 77 | 3 | 0 | |||||||||||||||||||
| SE | M Janvier | 710 | 6 | 1 | J Thompson | 1 | 4 | ||||||||||||||||||||
| B Fratangelo | 3 | 6 | 6 | B Fratangelo | 6 | 6 | |||||||||||||||||||||
| J-P Smith | 6 | 2 | 4 | B Fratangelo | 7 | 6 | |||||||||||||||||||||
 D Köpfer | 6 | 6 | D Köpfer | 5 | 3 | ||||||||||||||||||||||
| 7 | I Karlović | 4 | 4 | B Fratangelo | 6 | 6 | |||||||||||||||||||||
| 4 | R Opelka | 62 | 65 | 6 | C Ruud | 2 | 2 | ||||||||||||||||||||
 L Miedler | 77 | 77 | L Miedler | 4 | 1 | ||||||||||||||||||||||
| Q | S Fanselow | 6 | 5 | 6 | Q | S Fanselow | 6 | 6 | |||||||||||||||||||
 C İlkel | 2 | 7 | 0 | Q | S Fanselow | 1 | 0 | ||||||||||||||||||||
| M Polmans | 4 | 79 | 3 | 6 | C Ruud | 6 | 6 | ||||||||||||||||||||
| JC Aragone | 6 | 67 | 6 | JC Aragone | 1 | 64 | |||||||||||||||||||||
| Q | K King | 3 | 4 | 6 | C Ruud | 6 | 77 | ||||||||||||||||||||
| 6 | C Ruud | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 5 | A Menéndez Maceiras | 77 | 3 | 6 | |||||||||||||||||||||||
| LL | M Krueger | 65 | 6 | 1 | 5 | A Menéndez Maceiras | 6 | 6 | |||||||||||||||||||
 H Laaksonen | 6 | 4 | 1 |  T de Bakker | 4 | 3 | |||||||||||||||||||||
| T de Bakker | 4 | 6 | 6 | 5 | A Menéndez Maceiras | 6 | 6 | ||||||||||||||||||||
| Q | E King | 6 | 1 | 4 | WC | J. J. Wolf | 0 | 4 | |||||||||||||||||||
| WC | J. J. Wolf | 2 | 6 | 6 | WC | J. J. Wolf | 6 | 6 | |||||||||||||||||||
| WC |  A Geller | 3 | 4 | 3 | N Rubin | 3 | 2 | ||||||||||||||||||||
| 3 | N Rubin | 6 | 6 | 5 | A Menéndez Maceiras | 5 | 6r | ||||||||||||||||||||
| 8 | A Bolt | 7 | 3 | 6 | 8 | A Bolt | 7 | 6 | |||||||||||||||||||
| T Kokkinakis | 5 | 6 | 4 | 8 | A Bolt | 78 | 63 | 77 | |||||||||||||||||||
| WC | C Altamirano | 77 | 0 | WC | C Altamirano | 66 | 77 | 65 | |||||||||||||||||||
| D Evans | 62 | 0r | 8 | A Bolt | 6 | 6 | |||||||||||||||||||||
| Q | T Paul | 6 | 6 | 2 | L Harris | 3 | 4 | ||||||||||||||||||||
| Alt |  D King | 2 | 2 | Q | T Paul | 6 | 5 | 5 | |||||||||||||||||||
| D Young | 612 | 6 | 5 | 2 | L Harris | 4 | 7 | 7 | |||||||||||||||||||
| 2 | L Harris | 714 | 4 | 7 | |||||||||||||||||||||||
Mikhail Youzhny was the defending champion, but lost to Robin Haase in the quarterfinals.
Pablo Andújar won the title, defeating Juan Mónaco in the final, 6–3, 7–5.
Somdev Devvarman was the defending champion and successfully defended his title, defeating Yuki Bhambri in the final, 3–6, 6–4, 6–0.
Lleyton Hewitt was the defending champion, but chose to participate in the Davis Cup quarterfinals instead.
Rajeev Ram won the title, defeating Ivo Karlović in the final, 7–6(7–5), 5–7, 7–6(7–2).
Jordan Thompson was the defending champion but retired in the second round against Maverick Banes.
Noah Rubin was the defending champion but chose not to defend his title.
Evgeny Donskoy was the defending champion but chose not to defend his title.
Hiroki Moriya was the defending champion but chose not to defend his title.
Janko Tipsarević was the defending champion but chose not to defend his title.
John Isner was the defending champion and successfully defended his title, defeating Ryan Harrison in a rematch of the 2017 final, 5–7, 6–3, 6–4.
Alexander Zverev was the defending champion and successfully defended his title, defeating Alex de Minaur in the final, 6–2, 6–4.
Cameron Norrie was the defending champion but chose not to defend his title.
Matthew Ebden was the defending champion but chose not to defend his title.
Frances Tiafoe was the defending champion, but lost in the first round to Dan Evans.
Adrian Mannarino defeated Jordan Thompson in the final, 7–6(9–7), 6–3 to win the men's singles tennis title at the 2019 Rosmalen Grass Court Championships. It was Mannarino's maiden ATP Tour singles title in his seventh final. Thompson was also contesting for his maiden title.
Lloyd Harris was the defending champion but chose not to defend his title.
Rogério Dutra Silva was the defending champion but chose not to defend his title.
Nick Kyrgios was the defending champion, but retired from his first round match against Ugo Humbert due to a wrist injury.
Juan Pablo Varillas was the defending champion but chose not to defend his title.
Jannik Sinner was the defending champion but chose not to defend his title.
J. J. Wolf was the defending champion but lost in the semifinals to Stefan Kozlov.