The unidentified woman, who was in her 30s and from Garland, died on 25 July while waiting for her flight home to depart from Arizona.
The woman had trouble breathing and was given supplemental oxygen but died on the tarmac.
She had underlying health conditions but died from coronavirus, Dallas County judge Clay Jenkins said in a statement on Sunday.
It was not immediately clear if the woman was aware she had been infected with the disease when she died. Judge Clay did not say what airline she had been travelling on.
Garland County was not notified that the woman's death was coronavirus-related until a few days ago, judge Jenkins told TV station WFAA.
The Independent has contacted Garland Department of Health for additional comment.
The woman's death was a "reminder that there is no age restriction in coronavirus", Judge clay said. "I would strongly encourage people to not think they’re invincible from COVID because they don’t think they’re in a high-risk category," he added.
Coronavirus has killed some 220,000 Americans and infections continue to surge across the country.
In the past 24 hours, health officials have reported more than 64,000 new cases — 4,500 of tem in Texas and just under 400 logged in Dallas County.
Coronavirus fatality rates are highest among the elderly and those with underlying health conditions.
While it is rare that those in their 30s and with no underlying health conditions die from coronavirus, they are still susceptible to the disease and can transmit it to older people, which can be potentially fatal.