The singles division of the 1998 Croatian Bol Ladies Open was played on outdoor clay courts in Bol, Croatia as part of Tier IV of the 1998 WTA Tour. Mirjana Lučić was the defending champion and won in the final 6–2, 6–4 against Corina Morariu.
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.
Mary Joe Fernández (second round)
Fang Li (first round) Corina Morariu (final)
Gala León García (first round) María Sánchez Lorenzo (first round)
Sandra Kleinová (second round)