Angiostoma carettae n. sp. from the lungs of the loggerhead sea turtle, Caretta caretta, is described and illustrated. Angiostoma carettae is most similar to Angiostoma onycodactyla and Angiostoma stammeri in that lateral alae are absent, and there are 8 pairs of caudal papillae. Differences are that A. onycodactyla has only postcloacal papillae and that the 5 postcloacal papillae of A. stammeri are arranged differently from the 5 postcloacal papillae of A. carettae, with A. stammeri having 2 papillae near the cloaca and 3 distant, and A. carettae having with 3 papillae near the cloaca and 2 distant.