The species as a whole occurs throughout Borneo except for the southwest (where H. albibarbis is found), from the north bank of the Kapuas River clockwise around the island to the east bank of the Barito River (Groves 2001).

Hylobates muelleri muelleri
This taxon is found in southeast Kalimantan, Indonesia, approximately south of the Mahakam River and west of the Barito River (Groves 2001).

Hylobates muelleri funereus
This taxon is found in Brunei, Indonesia (Kalimantan) and Malaysia (Sabah and Sarawak). It ranges from the northeast of Borneo (Sabah) south to the Mahakam River and perhaps west to the Baram District and the IV Division of Sarawak (Groves 2001).

Hylobates muelleri abbotti
This taxon is found in Indonesia (Kalimantan) and Malaysia (Sarawak). It occurs north of the Kapuas River and east as far east as the Saribas District of Sarawak (Groves 2001).