Caenorhabditis portoensis is a species of nematode in the genus Caenorhabditis. First wild isolate sample (strain EG4788) was found on a rotting apple in Portugal.
Prior to 2014, it was referred to as C. sp. 6. It groups with C. virilis (sp. 13) in the 'Drosophilae' supergroup in phylogenetic studies.