The arrest was made Wednesday, roughly 10 minutes after campus-based police officers received a tip the student at Sterling High School may have a gun, reported Xinhua citing TV channel ABC13 news.
Houston police were reportedly investigating an allegation the student used the weapon to threaten an individual off campus Tuesday afternoon.
Police officers took the student into custody without incident and confiscated the weapon after searching him, according to the report.
The student told police he was carrying the weapon to protect himself from gang members in the neighbourhood surrounding the school.
The incident came as the country mourned the death of 20 schoolchildren and six adults in Friday's school shooting rampage in the US state of Connecticut. The shooting has rekindled the nationwide debate on gun control.