Mr Trump wrote on Truth Social: “I want to thank the great Lt. Governor of Texas, Dan Patrick, who served as Judge in the Ken Paxton Trial, and the Republican State Senators, for showing great Professionalism and Fairness.”
“Attorney General Paxton was fully acquitted on all 16 Impeachment Articles brought by the Texas Republican House. It is time that Speaker Dade Phelan resign after pushing this Disgraceful Sham!” he added.
“Congratulations to Attorney General Ken Paxton on a great and historic Texas sized VICTORY. I also want to congratulate his wonderful wife and family for having had to go through this ordeal, and WINNING!”
The former president also reposted a meme from a follower on Truth Social depicting the moment then-President George Bush was informed in a whisper by White House chief of staff Andrew Card of the attack on the World Trade Center in New York on September 11 2001.
The text reads: “They just acquitted Ken Paxton.”
Mr Paxton was acquitted on 16 impeachment articles brought before the state Senate.
A jury of 30 state senators, comprised of 19 Republicans and 12 Democrats, voted to acquit Mr Paxton on the articles accusing him of on abuse of power, bribery and other charges on Saturday morning.
Mr Paxton, who was elected to attorney general in 2015, will now go back to his office after none of the articles received the necessary two-thirds majority vote for conviction.
The Texas House impeached Mr Paxton in May on 20 articles – four of which were not voted on by the Senate on Saturday but were then dismissed in a follow-up vote.
The impeachment effort stemmed from accusations, brought forth by his former staffers, that Mr Paxton abused his power to benefit himself and a Texas real estate investor. They alleged that Mr Paxton gave the real estate investor special treatment in exchange for help paying for home renovations and engaging in an extramarital affair.
In the Senate trial, prosecutors and the defence spent nine days in the senate chambers presenting evidence and witness testimony in a historic trial that generated controversy among hard-right conservatives.
Mr Paxton, an ally of Donald Trump, received support from right-wing politicians like senator Ted Cruz and representative Marjorie Taylor Greene throughout the impeachment process who claimed the trial was a “travesty” and “witch hunt.”
Mr Trump backed Mr Paxton, calling the impeachment “shameful” and accusing “RINO” Texas officials of pursuing the trial for political reasons only.