The General Land Office (GLO) was established on December 22, 1836, by the First Congress of the Republic of Texas. The Office was originally responsible for managing the public domain by collecting and keeping records, providing maps and surveys and issuing land titles. On entering the Union in 1845, Texas' constitution charged the General Land Office with the supervision and management of the state's millions of acres of public lands. Since then GLO duties have evolved, but its core mission remains managing state lands and mineral-right properties totaling 20.3 million acres.

John P. Borden, the first commissioner, opened the office in Houston on October 1, 1837. He was enjoined by law to "superintend, execute, and perform all acts touching or respecting the public lands of Texas." The Constitution of the Republic of Texas honored all grants made by Spain and Mexico that were deemed valid by the republic; later, the state followed suit. The commissioner assembled from the archives of the former governments a record of valid land grants and translated them. Valid Spanish and Mexican grants cover 26,280,000 acres within the present boundaries of Texas. Some of these grants have received special confirmation by the state legislature, but most of them stand on the original titles from the governments of Spain and Mexico.

Borden also began to survey and register the new grants that the republic was issuing. Those from the public domain were made to colonists who had failed to receive their titles from Mexico, to new settlers, and to all soldiers who had rendered service in the Texas army. Headrights, military bounties, homestead preemptions, and veteran donations, issued by Borden and successive commissioners, brought the total number of acres granted to 75,647,668. Sales for the purpose of paying the public debt added 2,990,136 acres. For internal improvements to the Capitol, irrigation, drainage, iron works, and transportation facilities, including railroads, grants totaled 32,153,878 acres. For education (the University of Texas, Texas A&M, county schools, eleemosynary institutions, and the public school fund) grants totaled 49,530,334 acres. The individual grants, patents, and surveys by which the public domain has been disposed of are on file in the General Land Office, and a representation of each, surveyed by metes and bounds, appears on the original grantee map of the county in which the land is located.

Although the financial potential of Texas public land was generally limited to surface properties, over the years mineral resources became financially important. Texas ownership of mineral resources was confirmed by the United States Supreme Court on December 12, 1960, allowing the state to fully utilize mineral deposits of the Gulf area. The mineral revenues were consigned to the Permanent School Fund, which has received $6.8 billion since 1854.

New departments and equipment became necessary to manage the increased volume of business resulting from these trends. Land Office responsibilities cover other areas as well. The GLO's Archives and Records Division houses original Spanish, Mexican, and Republic of Texas land grants and associated documentation. The Recycling, Adopt-A-Beach, Coastal, and Oil Spill Prevention and Response programs work to protect Texas' natural resources. The GLO also encourages economic development through its natural gas marketing initiatives and loan programs offered to veterans through the Texas Veterans Land Board (VLB).

The General Land Office is headed by the elected land commissioner. The commissioner serves as chair of the Veterans Land Board and the School Land Board.