Tyler is a city in and the county seat of Smith County, Texas, United States. As of 2020, the population is 105,995. Tyler was the 38th most populous city in Texas (as well as the most populous in Northeast Texas) and 289th in the United States. It is the principal city of the Tyler metropolitan statistical area, which is the 198th most populous metropolitan area in the U.S. and 16th in Texas after Waco and the College Station–Bryan areas, with a population of 233,479 in 2020. The city is named for John Tyler, the tenth President of the United States.

In 1985, the international Adopt-a-Highway movement began in Tyler. After appeals from local Texas Department of Transportation officials, the local Civitan International chapter adopted a two-mile (three kilometer) stretch of U.S. Route 69 to maintain. Drivers and other motorists traveling on this segment of U.S. 69 (between Tyler and nearby Lindale) will see brown road signs that read "First Adopt-A-Highway in the World".

Tyler is known as the "Rose Capital of America" (also the "Rose City" and the "Rose Capital of the World"), a nickname it earned from a long history of rose production, cultivation, and processing. It is home to the largest rose garden in the United States, a 14-acre public garden complex that has over 38,000 rose bushes of at least 500 different varieties. The Tyler Rose Garden Center is also home to the annual Texas Rose Festival which attracts thousands of tourists each October.

As Northeast Texas and Smith County's major economic, educational, financial, medical and cultural hub, Tyler is host to more than 20,000 higher-education students; the University of Texas at Tyler; a university health science center; and regional hospital systems. It is the headquarters for Brookshire Grocery Company and many other large employers. Tyler is also home to the Caldwell Zoo and Broadway Square Mall, and the seat of Roman Catholic Diocese of Tyler and its Cathedral of the Immaculate Conception.