Social media users called it "insensitive" to use the massacre of January 1972 in Northern Ireland as a promotional tool.
"When promoting its Halloween Sundae ice cream, McDonald's Portugal developed a local market activation for a small number of its restaurants in Portugal," a spokesperson for McDonald's Portugal told The Guardian.
"The campaign was intended as a celebration of Halloween, not as an insensitive reference to any historical event or to upset or insult anyone in any way. We sincerely apologise for any offence or distress this may have caused."