Nineteen children and two teachers were killed at the school in May.
The Uvalde school district has dismissed its police chief following the mass shooting at Robb Elementary School in May.
Pete Arredondo was sacked on Wednesday after a unanimous vote by the Uvalde Consolidated Independent School District’s board of trustees.
Pressure has mounted on the police's response to the attack, which left nineteen children and two teachers dead.
Nearly 400 officers had rushed to the school, but police waited for over an hour to confront the 18-year-old gunman, and he remained in a school classroom, armed with an AR-15 style rifle.
Arredondo becomes the first police officer to lose his job following one of the deadliest school shootings in US history.
His dismissal was welcomed by an auditorium of parents and survivors of the massacre on 24 May, while other Uvalde residents have called for other officers to be held accountable.
Arredondo had been on leave since June 22 and was widely criticised for not ordering officers to act sooner.
His lawyer had argued that the former police chief had warned the Uvalde district about security issues in local schools one year before the shooting.
New measures to improve school safety in Uvalde include “non-scalable perimeter fencing” at school campuses, according to the school district, as well as additional security cameras, upgraded locks, and enhanced training for district staff.
Only one other officer — Uvalde Police Department Lt. Mariano Pargas, who was the city’s acting police chief on the day of the massacre — is known to have been placed on leave following the shooting at Robb Elementary School.