WASHINGTON — President-elect Donald J. Trump on Wednesday selected Sonny Perdue, the former governor of Georgia, to be his secretary of agriculture, two senior transition officials said, making his final cabinet selection two days before he is to be sworn in as president.

Mr. Perdue, a onetime veterinarian who was elected in 2003 as Georgia’s first Republican governor since Reconstruction, was a loyal supporter of Mr. Trump during his campaign. He had spoken with the president-elect in detail about his views on agriculture and trade, including changes that could be made to ensure that American producers are not placed at a disadvantage in international agreements.

The two officials confirmed the decision on the condition of anonymity because they were not authorized to comment on it before the formal announcement.

In an interview in November, Mr. Perdue said that Mr. Trump had quizzed him during their interview in Trump Tower over what he would do about unfair trade deals. He said the president-elect “believes that we in the U.S. have been sort of patsies over the years in the way we’ve dealt with our foreign competitors and international trade.”

If confirmed, Mr. Perdue would oversee an agency with a $150 billion budget. The Agriculture Department is in charge of farm policy and food safety, and it funds food stamps, nutrition programs and the United States Forest Service.