Gov. Greg Abbott, a fellow Republican, said in a statement that Ellzey will be "a strong and effective leader for the people of North Texas."
Ellzey was carrying more than 53% of the vote in Texas' 6th Congressional District with results from almost all precincts reported.
In May, Susan Wright, the widow of late Rep. Ron Wright, and Ellzey advanced to the runoff for Texas’ Sixth Congressional District, which many viewed as a bellwether for future contests. The runoff was also seen as a disappointment for Democrats who did not advance.
Wright's husband died of COVID-19 complications in February. She was gracious in her loss.
"Special elections are special, and this one was no exception," she tweeted. "I want to congratulate Congressman-elect Jake Ellzey on his victory. I am praying for his success & wish him well. I will never forget the kindness the people of #TX06 have shown Ron & I for so many years. Thank you."
The Trump factor played out on the periphery during the contest. In 2016, he won the district by 12 points, and lost some ground to candidate Joe Biden in 2020, after securing only a 3-point win there. Political insiders say the race between Ellzey and Wright was a litmus test for Trump in Texas and perhaps a gauge of his influence in general.
"The Trump candidate goes down in TX special That’ll give folks something to chew on!" David Axelrod, the former senior adviser to President Obama, tweeted.
Ellzey did not try to distance himself from Trump and instead sought to overcome the lack of Trump's backing by raising more money and showing off other endorsements, including the support of former Texas Gov. Rick Perry, the Associated Press reported.
"One of the things that we've seen from this campaign is a positive outlook — a Reagan Republican outlook for the future of our country — is what the people of the 6th District really, really want," Ellzey said, according to the Texas Tribune.
The Associated Press contributed to this report