"Linda has a tremendous background and is widely recognized as one of the country's top female executives advising businesses around the globe," Trump said in a statement. "She helped grow WWE from a modest 13-person operation to a publicly traded global enterprise with more than 800 employees in offices worldwide."
He continued, "Linda is going to be a phenomenal leader and champion for small businesses and unleash America's entrepreneurial spirit all across the country."
McMahon is the co-founder of the professional wrestling franchise WWE along with her husband, Vince McMahon, and twice a former Republican Senate candidate from Connecticut. She stepped down from her duties at WWE in 2009 and ran two failed bids for the Senate in 2010 and 2012.
She's donated $6 million in August and September to Rebuilding America Now, a super PAC that supported Trump's presidential bid. And she gave an additional $1 million in October to another super PAC backing Trump.
She tweeted on Wednesday, "Honored to be appointed by President-Elect @realDonaldTrump to serve as head of @SBAgov advocating for our small businesses & entrepreneurs!"
McMahon will have to be approved by the Senate before she becomes the administrator of the SBA. However, Sen. Dick Blumenthal, who ran against McMahon in 2010, told CNN's Manu Raju that he'd likely vote for her. He called her a reasonable voice in Trump's economic team.
McMahon wasn't always a fan. During the Republican primary, she told Yahoo's Katie Couric that she was offended by Trump's comments about women, calling them "deplorable."
"He's not helping, certainly, to put women in the best light," McMahon said. "Maybe he regrets them, maybe he doesn't. I realize he punches hard when he punches back, but that's just over the top."
But after the primaries, McMahon told the Associated Press that even though Trump wasn't her first choice for the nomination, she became a strong supporter of the business mogul.
"Once you're his friend, he is loyal to the end," she said. "He's an incredibly loyal, loyal friend."