Ziegler, who became the youngest White House press spokesman after he joined Nixon's 1968 presidential campaign, died of a heart attack in California on Monday.
He is remembered for describing the break-in at a Democratic Party office that set off the scandal as a "third-rate burglary" - a remark which came back to haunt him.
In a book published online in 2002 by former Nixon White House lawyer John Dean, Ziegler was mentioned as one of four people who could have been the "Deep Throat" source involved in revealing the Watergate scandal. Ziegler denied it.
The chain-smoking Deep Throat famously helped Washington Post reporters Bob Woodward and Carl Bernstein unravel the affair by providing guidance at late-night meetings in underground car parks.
John Dean was at the centre of the Watergate hearings, telling investigators that he had discussed the Watergate cover-up with President Nixon at least 35 times.
Friends said Ziegler had been working on a book about his tumultuous years alongside President Nixon.
Loyal
Ziegler spoke for the White House on such historic events as the opening of relations with China and the Vietnam War, but his name is most commonly associated with the Watergate scandal.
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I'm proud of what I did as press secretary, I don't feel the need to apologise; there are some things, however, I would have done differently
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Ron Ziegler
He was a strident Nixon defender until the public release of tapes that made it clear the president and his top aides had engaged in a vast cover-up.
He would later say he had not been told about their efforts to hide the truth.
Ziegler stayed with the president even after Nixon's fall from grace.
"I was the only one on that plane... with Nixon when power changed hands," he said.
"I was there with Nixon in exile... I'm proud of what I did as press secretary. I don't feel the need to apologise. There are some things, however, I would have done differently."
Break-in scandal
On 17 June 1972, five men were caught trying to break into the offices of the Democratic National Committee in the Watergate complex in Washington.
The intruders were adjusting bugging equipment and photographing documents.
The Republican Party, the FBI, the CIA, the Justice Department, the attorney general, the White House, and eventually the president all became embroiled in the ensuing cover-up.
When secret tape recordings of Nixon's complicity finally came to light, he was left with no choice but to resign.