A new taxon of a broad-snouted goniopholidid, Siamosuchus phuphokensis, gen. et sp. nov., was discovered in the Sao Khua Formation (ante-Aptian), northeastern Thailand. The specimen is described on the basis of an incomplete skeleton showing the premaxillae, maxillae, nasals, left lacrimal, frontal, left jugal, right postorbital, caudal part of the cranial table, most of the right part of the postcranial skeleton, and several heavily sculptured osteoderms. S. phuphokensis is distinguished from the other broad-snouted goniopholidids on the basis of the following characters: penetration of the nasals in the narial border; presence of a robust and high median ridge on the interorbital surface; lateral margin of the frontal forming the medial edge of the orbit; supraoccipital exhibiting a wide pentagonal shape. A phylogenetic analysis using 101 characters for 29 mesoeucrocodylian taxa and 3 outgroup taxa supports the monophyly of the family Goniopholididae. In addition, the Thai specimen forms a clade with the European Goniopholis. Based on our strict consensus tree, the generic name Goniopholis should be restricted to the European forms only.