Bagrichthys majusculus is one of seven species of bagrid catfish in the genus Bagrichthys. It is endemic to Thailand.
The Bagrichthys majusculus has a mouth that is relatively large and broad. They have an oral dentition with teeth that are homodent that is well-developed. They have a gill-raker count of 10-13, a dorsal spine that is moderately long with 15-27 serrations.[1]