Texas Rangers, a body of law enforcement in the state of Texas which is the oldest law enforcement body in North America with statewide jurisdiction and serves as a State Bureau of Investigation.

At a consultation of the Provisional Government of Texas, Elder Daniel Parker offered a resolution to establish the Texas Rangers. He proposed three companies of rangers, one for the area between the Brazos and Trinity Rivers, one for the area between the Brazos and Colorado Rivers, and one for the area east of the Trinity River. This was instituted by Texas lawmakers on November 24, 1835. There were 56 men in these three companies. Each company was commanded by a captain and two lieutenants. Their superior had the rank of major and answered to the commander-in-chief of the army. Parker's brother, Silas Mercer Parker, was made a superintendent over 25 men working the "Brazos to Trinity" area.

In Texas' Revolution for independence from Mexico, the rangers served as scouts and couriers. After independence was gained and the land became the Republic of Texas, the Texas Rangers saw little duty under President Sam Houston. When Mirabeau B. Lamar became President in 1838, he rejected Houston's frontier policies of friendship with the Indians. He engaged the Rangers in war against the Indians, and succeeded in weakening their power. Throughout the years of the Republic, the Texas Rangers protected the frontier against invasion from Mexico and attacks from Indians.

One hundred years after the establishment of the Texas Rangers, in 1935 the Texas legislature established the Texas Department of Public Safety. At that time, the Texas Rangers became one of three units of the Texas DPS.

In Arizona the general plan of the Texas Rangers was followed in organizing the Arizona Rangers, likewise in New Mexico with the New Mexico Mounted Police.

The TV series Walker, Texas Ranger, created in 1993 and starring martial arts practitioner and instructor Chuck Norris as Cordell Walker, has drawn much attention to this Texas law enforcement body.

There was a 1960's television series based on the Texas Rangers.