The lieutenant governor of Texas is the second-highest constitutional officer in the U.S. state of Texas. It is the second-highest rank in the state government, behind only the governor.

The lieutenant governor serves as the first person in the gubernatorial line of succession, as an ex officio member of several state boards, and as the president of the Texas Senate. Unlike most lieutenant governors in the U.S., whose position in their respective state senates are largely ceremonial, the lieutenant governor of Texas plays an active role in running the chamber.

The lieutenant governor is elected every four years during the state's midterm elections. It is elected separately from the governor and has no term limits. The current lieutenant governor is Dan Patrick, who has served since January 20, 2015.

Under the provisions of the Texas Constitution, the lieutenant governor is president of the Texas Senate. Unlike with most other states' senates and the U.S. Senate, the lieutenant governor regularly presides over the chamber rather than delegating this function to the president pro tempore or a majority leader. By the rules of the Senate, the lieutenant governor establishes all special and standing committees, appoints all chairpersons and members, and assigns all Senate legislation to the committee of his choice. The lieutenant governor decides all questions of parliamentary procedure in the Senate and has broad discretion in following Senate procedural rules.

The lieutenant governor is an ex officio member of several statutory bodies, including the Legislative Budget Board, the Legislative Council, and the Legislative Audit Committee, which have considerable sway over state programs, the budget and policy. The lieutenant governor is also a member of the Legislative Redistricting Board (together with the speaker of the House, attorney general, comptroller, and land commissioner), which is charged with adopting a redistricting plan for the Texas House of Representatives, Texas Senate, or U.S. House of Representatives after the decennial census if the Legislature fails to do so.

The lieutenant governor assumes the powers of the governor of Texas when the governor is out of the state or otherwise unable to discharge the office.

In the case of a vacancy in the lieutenant governor's office, the Senate elects one of its members to act as President of the Senate until the next statewide office election, in effect becoming the lieutenant governor. A senator elected as presiding officer in this way retains their district seat and the voting privileges entailed with his Senate election.

Texas is one of the few states that vests significant power in the office of lieutenant governor, making it among the most influential. By contrast, the lieutenant governor position in other states has few (if any) legislative responsibilities, akin to the vice president of the United States.