The emergence of carbapenem-resistant Acinetobacter baumannii, responsible for causing nosocomial infections, has been becoming a significant global health issue. In this article, we report the complete genome sequence of bacteriophage B-B1251 (YMC/09/02/B1251 ABA BP), which causes lysis of a carbapenem-resistant A. baumannii strain. The bacteriophage belongs to the family Podoviridae and has a double-stranded circular DNA genome with a length of 45,364 bp and a 39.05% G+C content. Genome analysis showed that it had no similarity to other previously reported bacteriophages capable of infecting A. baumannii.