Authorities said the crash happened just after 7 a.m. when the bus was traveling westbound on FM 2090 at Philmore.
The bus driver was picking up Creighton Elementary School students and had the bus stop sign activated.
A woman driving a pickup truck eastbound stopped for the bus, but a male driver in a Mazda driving behind the pickup didn't see the truck stop.
The driver slammed into the back of the pickup, causing it to hit the bus and then slide into a ditch.
The rear bumper of the bus struck the pickup windshield, barely missing the driver
Authorities said all 23 students on the bus were uninjured.
The woman driving the pickup was transported to the hospital in stable condition, and the driver of the Mazda was uninjured.
The department of public safety is investigating the crash.