Orphnaecus adamsoni is a species of tarantula found in the Dinagat Islands, Philippines.

[2] Orphnaecus adamsoni was discovered by Julius John Salamanes, Jhayson Mark Santos, Eleanor Austria, and Gil Gabriel Villancio[a] of Adamson University in the province of Dinagat Islands, Philippines.

The team named the species after the university and published their discovery in August 2022 on the open-access journal Biodiversitas.

[2] Salamanes et al. (2022) noted it closely resembles Orphnaecus kwebaburdeos in Polillo Islands, Quezon Province in Luzon.

However, it has rounded carapace and shorter leg segments, more clavate paddle-shaped maxillary lyra, and a different habitat.