1991 KAL Cup Korea Open
Date	15–22 April
Edition	5th
Category	World Series (Free Week)
Draw	32S / 16D
Prize money	$140,000
Surface	Hard / outdoor
Location	Seoul, South Korea
Champions
Singles
Patrick Baur[1]
Doubles
Alex Antonitsch / Gilad Bloom[2]
← 1990 · KAL Cup Korea Open · 1992 →

The 1991 KAL Cup Korea Open was a men's tennis tournament played on outdoor hard courts that was part of the World Series of the 1991 ATP Tour. It was the fifth edition of the Seoul Open and was played at Seoul in South Korea from 15 April through 22 April 1991. Unseeded Patrick Baur won the singles title.

Finals

Singles

Patrick Baur defeated Jeff Tarango 6–4, 1–6, 7–6^(7–5)

• It was Baur's 2nd title of the year and the 4th of his career.

Doubles

Alex Antonitsch / Gilad Bloom defeated Kent Kinnear / Sven Salumaa 7–6, 6–1

• It was Antonitsch's only title of the year and the 4th of his career. It was Bloom's 1st title of the year and the 3rd of his career.