Abbott's gray gibbon is a gray gibbon of forests in northwestern Borneo. A 2023–2024 survey in Sarawak recorded it in riverine and beach forests.
Its coat is medium to mouse gray. Many individuals reportedly lack a clear dark cap on the crown, although this feature is not consistent.
A July 2023–February 2024 survey in Tanjung Datu National Park, Sarawak, recorded the species at all four sites. These included riverine forest along Pasir Antu Laut Trail and beach forest along Telok Melano Trail. It has distinctive duet calls, and researchers used both visual observations and calls to identify it.
An extinction-risk assessment has not been added yet.