Protozoans are widely distributed, and several species may parasitize the digestive tracts of cats (Felis catus), and can be transmitted to humans. The present study aimed to evaluate the species and occurrence of gastrointestinal protozoans in cats in the city of Londrina, Paraná, Brazil. A total of 206 cat fecal samples were tested, of which 141 were from shelter animals, and 65 were from pets owned by local people. Samples were processed by parasitological techniques. Coproparasitological techniques (Willis, Faust and Ziehl-Neelsen) were performed for detection of protozoan parasites. Subsequently, all samples were processed by PCR protocols specific to Toxoplasma gondii, Giardia spp., and Cryptosporidium spp. PCR products from positive samples were selected for sequencing. No samples were found to be positive for Cryptosporidium spp. using the Ziehl-Neelsen technique. Using specific PCR protocols, 1/206 (0.48%) samples tested positive for Cryptosporidium spp. After purification, this one positive sample was sequenced, and it demonstrated a 100% identity match to Cryptosporidium muris. Using specific PCR protocols, 13/206 (9.22%) cat fecal samples tested, including 2/65 (3.08%) pet cat fecal samples, were positive for T. gondii. PCR analysis revealed that 37/206 (17.96%) of cat fecal samples were positive for Giardia spp., including 27/141 (19.15%) of shelter cat fecal samples, and 10/65 (15.38%) pet cat fecal samples (p = 0.5124). When sequenced, these positive samples showed a 100% identity match with Giardia duodenalis. This study demonstrated that infections with Cryptosporidium spp., Toxoplasma gondii, and Giardia duodenalis are present in the population of both pet cats and shelter cats in the city of Londrina. This poses a risk to public health, because these parasites have a high zoonotic potential. ResumoOs protozoários são amplamente distribuídos, e várias espécies podem parasitar o trato digestivo de gatos (Felis catus) e podem ser transmitidas para humanos. O presente estudo teve como objetivo avaliar as espécies e a ocorrência de protozoários gastrintestinais em gatos na cidade de Londrina, Paraná, Brasil.