President Trump on Wednesday pardoned Michael G. Grimm, a former New York representative who pleaded guilty in 2014 to felony tax evasion, according to a White House official.

Mr. Grimm, a Republican, represented Staten Island and part of Brooklyn in the House of Representatives from 2011 until he resigned in 2015. On Wednesday, a White House spokesman compared Mr. Grimm’s prosecution to the president’s own legal troubles, which Mr. Trump has long derided as a witch hunt.

“President Trump knows firsthand the impact of a weaponized justice system,” said the spokesman, Harrison Fields. He said the president was “using his constitutional authority to right the wrongs of Americans who’ve been impacted by this corrupt system.”

Mr. Grimm was indicted in 2014 after he failed to report nearly $1 million in gross receipts and hundreds of thousands of dollars in employee wages from a Manhattan restaurant he had owned, prosecutors said. After pleading guilty to one felony charge of tax fraud, he was sentenced to eight months in prison, serving seven.

Reporting by The New York Times indicated that Mr. Grimm also engaged in a range of other potential crimes, including campaign finance and other possible fraud. He was not charged in connection with any of that activity.

In recent years, he has worked as an on-air personality at the right-wing television network Newsmax, and has been an enthusiastic public supporter of Mr. Trump’s.