On August 13, 1983, DART was created when 58% of the voters in 14 cities and Dallas County cast more than 101,000 ballots in favor of regional transportation. 

In January 1984, the voter-approved one-cent sales tax takes effect, and DART officially begins operations. Staff began work on bus service improvements, rail transit, high occupancy vehicle (HOV) lanes, carpooling, and mobility-impaired transit planning.

The first phase of suburban bus service was introduced in the spring of 1984 through a contract with Trailways Commuter Transit. DART began operating midday service in June, adding 57 buses on 37 area routes. By the end of the year, the agency added 74 buses on 54 routes, expanding rush hour service on 33 routes and introducing more crosstown service.

During 1985-1986, DART rapidly expands bus service in the cities outside of Dallas, making it one of the fastest bus network startups in transit history.

DART formally acquired the Dallas Transit System and its operations from the City of Dallas in February 1988. In April, the agency purchased over 34 miles of railroad right-of-way (ROW) from the Southern Pacific Transportation Company, most for future transit use.

By the end of 1988, bus ridership reached 150,000 passenger trips per weekday.

In 2000, the agency completed the Northwest Corridor Major Investment Study and the Southeast Corridor Major Investment Study (MIS), finalizing the light rail routes for what would become the Green and Orange lines, serving Carrollton, Farmers Branch, Irving, Dallas Fort Worth International Airport, as well as the Fair Park and Pleasant Grove areas of Dallas. That August, voters in DART's 13 member cities approved $2.9 billion in long-term financing to upgrade and accelerate future light rail lines to these areas and Rowlett.  

On December 3, 2001, the Trinity Railway Express – a joint project of DART and the Fort Worth Transportation Authority (now Trinity Metro) – expanded to link Dallas and Fort Worth with passenger rail service for the first time since the mid-1930s. 

By the end of 2002, light rail reaches North Dallas, Garland, Richardson, and Plano, with northern extensions of the Blue and Red Lines. 

In November 2004, DART opened Victory Station at the American Airlines Center, the first station of the Northwest Corridor rail expansion. 

In July 2009, the Rosa Parks Plaza opened in Downtown Dallas at the corner of Elm and Lamar, creating a new type of bus passenger facility. The plaza was named after the iconic civil rights hero, offering a park-like setting. 

The first three miles and four new stations of the Green Line opened in September 2009 – just in time for the State Fair of Texas® – with service from MLK, Jr. Station in South Dallas to Victory Station near the American Airlines Center.

In March 2020, the onset of the novel coronavirus (COVID-19) pandemic profoundly impacted DART’s operations. DART, the Denton County Transportation Authority (DCTA), Fort Worth's Trinity Metro, and the Trinity Railway Express (TRE) aggressively expand agency-wide cleaning and safety protocols in response to the novel coronavirus (COVID-19) pandemic.

As many in North Texas remained home under shelter-in-place orders, DART implemented temporary service adjustments for bus and light rail that reflected the ridership demand. The agency then made good use of underutilized buses and paratransit vehicles beginning in April. DART partnered with the Dallas Independent School District and Garland Independent School District to deliver meals to students and with the City of Dallas to distribute care packages to seniors. DART Paratransit Services drivers helped the agency’s paratransit customers by picking up and delivering food and medicine and worked with Catholic Charities Dallas to deliver meals to its Brady Center seniors.

By July 2020, the agency had installed respiratory droplet shields on the entire fleet of more than 600 buses as a safety measure to protect bus operators and passengers who continued to drive or ride during the pandemic. In August, DART installed face masks and hand sanitizer dispensers on all buses, light rail vehicles, and streetcars. In October 2020, DART restored 90% of service to pre-pandemic levels. 

In April 2021, DART celebrated the opening of the Hidden Ridge Station at Carpenter Ranch in Irving, an infill station on the Orange Line and the 65th station in the DART Rail network. Developed in partnership with the City of Irving and Verizon Communications, the new station was built to provide transportation options for the Hidden Ridge development. 

The DART Board of Directors unanimously approved the DARTzoom Final Bus Network Plan, which included a complete redesign of the DART bus network and the expansion of the GoLink service, in September 2021. The New Bus Network went into effect on January 24, 2022, with greater frequency, longer service hours, and improved access to destinations. Yet by June of that year, DART implemented temporary service frequency adjustments on 31 of its 97 bus routes due to the ongoing nationwide shortage of bus operators. 

In February 2023, DART Human Resources began hosting hiring fairs at DART Headquarters to find applicants for open positions in transit operations (bus and rail operators and mechanics), administrative fields, and the DART Police Department. The aggressive hiring efforts have enabled the agency to improve its service reliability and security.