Abstract Motivation We introduce HaploGrouper, a versatile software to classify haplotypes into haplogroups on the basis of a known phylogenetic tree. A typical use case for this software is the assignment of haplogroups to human mitochondrial DNA (mtDNA) or Y-chromosome haplotypes. Existing state-of-the-art haplogroup-calling software is typically hard-wired to work only with either mtDNA or Y-chromosome haplotypes from humans. Results HaploGrouper exhibits comparable accuracy in these instances and has the advantage of being able to assign haplogroups to any kind of haplotypes from any species—given an extant annotated phylogenetic tree defined by sequence variants. Availability and implementation The software is available at the following URL https://gitlab.com/bio_anth_decode/haploGrouper. Supplementary information Supplementary data are available at Bioinformatics online.