2018 Seoul Open Challenger
Date	30 April – 6 May
Edition	4th
Surface	Hard
Location	Seoul, South Korea
Champions
Singles
Mackenzie McDonald
Doubles
Toshihide Matsui / Frederik Nielsen
←  2017 · Seoul Open Challenger ·  2019 →

The 2018 Seoul Open Challenger was a professional tennis tournament played on outdoor hard courts. It was the fourth edition of the tournament. It was part of the 2018 ATP Challenger Tour. It took place in Seoul, South Korea, between 30 April and 6 May 2018.

Country	Player	Rank1	Seed
CAN	Vasek Pospisil	82	1
ISR	Dudi Sela	96	2
AUS	Jordan Thompson	98	3
TPE	Lu Yen-hsun	112	4
USA	Mackenzie McDonald	141	5
JPN	Go Soeda	145	6
TPE	Jason Jung	154	7
JPN	Tatsuma Ito	176	8

• ¹ Rankings as of 23 April 2018. ^[1]

The following players received wildcards into the singles main draw:

• Chung Yun-seong
• Hong Seong-chan
• Kim Young-seok
• Park Ui-sung

The following player received entry into the singles main draw as a special exempt:

• Kamil Majchrzak

The following players received entry from the qualifying draw:

• Makoto Ochi
• Son Ji-hoon
• Renta Tokuda
• Yosuke Watanuki

• Mackenzie McDonald def. Jordan Thompson 1–6, 6–4, 6–1.

• Toshihide Matsui / Frederik Nielsen def. Chen Ti / Yi Chu-huan 6–4, 7–6^(7–3).