Bellubrunnus (meaning "the beautiful one of Brunn" in Latin) is an extinct genus of rhamphorhynchid pterosaur from the Late Jurassic (Kimmeridgian stage) of southern Germany.

Bellubrunnus is distinguished from other rhamphorhynchids by its lack of long projections on the vertebrae of the tail, fewer teeth in the jaws, and wingtips that curve forward rather than sweep backward as in other pterosaurs.

The specimen is currently housed in the Bürgermeister-Müller-Museum, although it is cataloged for, and a possession of, the Bayerische Staatssammlung für Paläontologie und historische Geologie.

It comes from a quarry at Kohlstatt near the village of Brunn, Upper Palatinate, in a layer of rock that underlies the better-known Solnhofen Limestone.

The unfused scapulocoracoid bone — with the straight scapula ("sc") and coracoid ("co") still separate — in the pectoral girdle suggests that it may have been less than one year old.

The large hatchet-shaped deltopectoral crest of the humerus ("hu") or upper arm bone, in this case more precisely in the form of a rounded tongue, is one of the features that indicate that Bellubrunnus is a member of Rhamphorhynchidae, but the great length of the humerus in comparison to the length of the femur ("fe") or upper leg bone, with a ratio of 1.4, distinguishes it from other rhamphorhynchids and is a second autapomorphy.

O'Sullivan and Martill (2015) found the majority of the purported distinguishing characters of Bellubrunnus to be problematic, stressing especially the lack of in-depth studies into the way rhamphorhynchid skeletons changed through ontogeny; this means that it remains uncertain whether the differences between Bellubrunnus and Rhamphorhynchus do indeed confirm that they are distinct taxa or whether these differences are merely ontogenetic in nature.

The authors, however, noted that two characters of the species Bellubrunnus rothgaengeri (the lack of elongate caudal supports on the vertebrae and the anteriorly curving wing phalanx IV) make it possible that it is not conspecific with Rhamphorhynchus muensteri.

The stratigraphic unit in the Brunn quarry where the Bellubrunnus holotype was found is almost identical to the Solnhofen Limestone, but slightly older.

Bellubrunnus may have occupied the same ecological niche as Rhamphorhynchus, that of a piscivore or fish-eater, and may even have been its direct evolutionary ancestor, forming a chronogenus relation within a single persisting population, although more fossils are needed to confirm this relationship.