Will Hurd made the decision "in order to pursue opportunities outside the halls of Congress to solve problems at the nexus between technology and national security," he said in a statement.
The representative has criticized Trump's attacks on ethnic minority lawmakers as "unbecoming of the leader of the free world."
Hurd was one of just four Republicans in the House to vote for a resolution last month condemning the president's "racist comments."
"There is no room in America for racism, sexism, antisemitism, xenophobia and hate," he tweeted at the time.
Remarking on his decision to not seek reelection, Hurd said: "Two centuries ago, I would have been counted as three-fifths of a person, and today I can say I've had the honor of serving three terms in Congress."
"America has come a long way and we still have more to do in our pursuit of a more perfect union. However, this pursuit will stall if we don't all do our part," he said.