Magruder died May 11 in Danbury, Connecticut, Hull Funeral Service director Jeff Hull said Friday.
Magruder, a businessman when he began working for the Republican president, later became a minister, serving in California, Ohio and Kentucky. He also served as a church fundraising consultant.
He spent seven months in prison for lying about the involvement of Nixon's re-election committee in the 1972 break-in at Washington's Watergate complex, which eventually led to the president's resignation.
In a 2008 interview, Magruder told The Associated Press he was at peace with his place in history. The interview came after he pleaded guilty to reckless operation of a motor vehicle following a 2007 car crash.
"I don't worry about Watergate, I don't worry about news articles," Magruder said. "I go to the court, I'm going to be in the paper - I know that."
Magruder, who moved to suburban Columbus in 2003, served as Nixon's deputy campaign director, an aide to Nixon Chief of Staff H.R. Haldeman and deputy communications director at the White House.
Magruder said in 2003 that he was meeting with John Mitchell, the former attorney general running the Nixon re-election campaign, when he heard the president tell Mitchell to go ahead with the plan to break into the Democratic Party headquarters at the Watergate office building.
Magruder previously had gone no further than saying that Mitchell approved the plan to get into the Democrats' office and bug the telephone of the party chairman, Larry O'Brien.
He made his claims in a PBS documentary and an Associated Press interview.
He said he met with Mitchell on March 30, 1972, and discussed a break-in plan by G. Gordon Liddy, a former FBI agent who was finance counsel at the re-election committee. Mitchell asked Magruder to call Haldeman to see "if this is really necessary."
Haldeman said it was, Magruder said, and then asked to speak to Mitchell. The two men talked, and then "the president gets on the line," Magruder said.
Magruder said he could hear Nixon tell Mitchell, "John, ... we need to get the information on Larry O'Brien, and the only way we can do that is through Liddy's plan. And you need to do that."
Historians dismiss the notion as unlikely, saying there was no evidence Nixon directly ordered the break-in.
Magruder stuck to his guns in the 2008 AP interview, saying historians had it wrong.
He became a born-again Christian after Watergate, an experience he described in his 1978 biography, "From Power to Peace."
"All the earthly supports I had ever known had given way, and when I saw how flimsy they were I understood why they had never been able to make me happy," he wrote. "The missing ingredient in my life was Jesus Christ and a personal relationship with him."
Magruder, who was born in New York City on Nov. 5, 1934, held sales and management jobs at several companies, including paper company Crown Zellerbach and Jewel Food Stores. He also became active in Republican politics.
He received a master's degree in divinity from Princeton Theological Seminary in 1981, then worked at a Presbyterian church in California, First Community Church in suburban Columbus and First Presbyterian Church, a 200-year-old parish in Lexington, Kentucky.
But he could never fully leave the scandal behind.
In 1988, Dana Rinehart, then Columbus mayor, appointed Magruder head of a city ethics commission and charged him to lead a yearlong honesty campaign. An ethics commission "headed by none other than (are you ready America?) Jeb Stuart Magruder," quipped Time magazine.
At Dallas-based RSI-Ketchum, a church fundraising consulting group, Magruder shielded his Watergate reputation at first, but later opened up because of people's interest in it, said Jim Keith, the company's former senior vice president.
"He finally grew where he was open enough to be able to talk with them about it," Keith, now retired in Dallas, said Friday.
Magruder had new struggles in retirement.
Besides the 2007 crash - when accident investigators concluded he had a stroke - he pleaded no contest in 2003 to disorderly conduct after police in the Columbus suburb of Grandview found him passed out on a sidewalk.
Despite his problems, Magruder continued to advocate doing the right thing in retirement. He told The Columbus Dispatch in 2003 that Americans should work for moral change by helping the homeless or working with Habitat for Humanity.
In his 1974 book, "An American Life: One Man's Road to Watergate," Magruder blamed his role in the scandal on ambition and losing sight of an ethical compass.
"Instead of applying our private morality to public affairs, we accepted the President's standards of political behavior, and the results were tragic for him and for us," he wrote.