The 2019 Busan Open was a professional tennis tournament played on hard courts. It was the eighteenth edition of the tournament which was part of the 2019 ATP Challenger Tour. It took place in Busan, South Korea between 6 and 12 May 2019.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Lithuania | Ričardas Berankis | 102 | 1 | |
 Ukraine | Sergiy Stakhovsky | 115 | 2 | |
 Canada | Brayden Schnur | 116 | 3 | |
 Slovakia | Lukáš Lacko | 121 | 4 | |
| Jason Jung | 132 | 5 | ||
 Cyprus | Marcos Baghdatis | 135 | 6 | |
 Russian Federation | Evgeny Donskoy | 136 | 7 | |
 India | Ramkumar Ramanathan | 146 | 8 | |
 Serbia | Nikola Milojević | 148 | 9 | |
 Japan | Tatsuma Ito | 153 | 10 | |
 Korea, Republic of | Kwon Soon-woo | 162 | 11 | |
 Belgium | Ruben Bemelmans | 163 | 12 | |
| Japan | Yūichi Sugita | 182 | 13 | |
| Japan | Hiroki Moriya | 183 | 14 | |
| Japan | Go Soeda | 200 | 15 | |
| Japan | Yasutaka Uchiyama | 227 | 16 |
The following players received wildcards into the singles main draw:
Hong Seong-chan Kim Cheong-eui Kim Young-seok Nam Ji-sung Song Min-kyuThe following players received entry from the qualifying draw:
Makoto Ochi
Xia ZihaoSee main article: 2019 Busan Open – Singles.
Ričardas Berankis def. 
Andrew Harris 7–6(7–5), 6–2.See main article: 2019 Busan Open – Doubles.
Toshihide Matsui / Vishnu Vardhan 7–6(9–7), 6–1.