The former president and Laura Bush voted in person on 15 October, according to the Dallas Morning News.
There had been speculation that Mr Bush might endorse Joe Biden, but when the former vice president’s campaign reached out they were reportedly told that the 43rd president was not getting involved in the race.
Mr Bush famously selected “none of the above” on election day in 2016 when Mr Trump battled with Hillary Clinton for the White House.
Mr Bush’s spokesman Freddy Ford said that the couple would not be making their votes public as the former president was “retired” from politics.
Mr Trump is locked in a tight race in Texas with Mr Biden.
It would be the first time that Texas selected a Democrat for president since Jimmy Carter beat President Gerald Ford in the state in 1976.
Mr Bush carried his home state in 2000 and 2004, as did his father, former President George HW Bush, in 1988 and 1992.
Mr Bush’s brother, Jeb Bush, clashed with Mr Trump on the campaign trail in 2016 as both men fought top secure the Republican nomination for president.
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