The crash happened around 10:30 p.m. Wednesday on Hollister Road and SH-249.
Investigators said the Harris County sheriff's deputy was leaving a gas station when a woman in another car missed the turn into the business.
That's when the woman started traveling the wrong-way on Hollister, colliding head-on with the deputy, officials said.
Deputies said the woman showed no signs of intoxication and is cooperating with investigators.
Neither the woman nor the deputy were injured in the crash.