"It has been my joy and honour to serve as your premier," he said.
McGuinty's tenure at the helm of Ontario politics made him the longest-serving current premier in the country.
McGuinty's successor is being chosen in downtown Toronto at the Mattamy Athletics Centre, on the site of the former Maple Leaf Gardens, the place where he won the leadership of the party back in 1996.
He recalled his wife's reaction to his victory.
"It was here, 16 years ago, when they announced the results, that Terri grabbed me, leaned over and gently whispered in my ear: 'You said you weren’t going to win.'"
"Nobody was more terrifed than me when I won," he said.
McGuinty pointed to education, health care, the environment and the economy as areas the party could be proud of during his tenure.
He also touched on unity as the party moves ahead.
"To you, my Ontario Liberal friends, I ask you always to remember how we succeed: We work hard. We work together. We are true to ourselves. And we put Ontarians first."
The party paid tribute to McGuinty with dancing, videos and musical performances by Matt Dusk, who sang the Paul Anka-penned My Way, and Julia Bentley, daughter of Energy Minister Chris Bentley.
Each of the six candidates vying to replace McGuinty also made brief remarks to the assembled party members.
"This is not about us, the candidates," said Gerard Kennedy. "This is about a very special man."
Charles Sousa recalled how he spilled water on McGuinty during question period just before the premier was to speak. McGuinty shook it off, saying, "'I'm glad it wasn't wasn't coffee or wine.'"
"Despite that faux pas, I still survived the next cabinet shuffle," Sousa said.
'If we could do half the success you've had, we would be delighted," said Sandra Pupatello. "You kept us up when we needed to be up."
Many of the candidates also hailed McGuinty's wife, Terri, and their four children
McGuinty made the surprise announcement in October 2012 that he was stepping down as leader of the Ontario Liberal Party after 16 years in that position and nine years as premier of the province. At the same time, he said he asked the lieutenant-governor to prorogue the legislature to give the government the opportunity to work on reaching wage-freeze agreements with public-sector workers.
First elected MPP for Ottawa South in 1990, McGuinty became leader of the party in 1996. He was a surprise choice; after placing fourth on the first ballot, McGuinty began gathering support. He eventually defeated Gerard Kennedy, that race's frontrunner, on the fifth ballot.
McGuinty went on to lead the Liberals to two majority governments — in 2003 and 2007.
However, in the 2011 vote, the party was reduced to a minority government with 53 of the Ontario Legislature's 107 seats.
After Friday's tribute, the convention delegates will move Saturday to the selection of a new party leader. There are 1,864 elected delegates, who are pledged to support a specific candidate on the first ballot, plus roughly 420 ex-officio delegates made up of former candidates and party bigwigs whose votes are not pledged to a specific candidate.
Results of first-ballot voting are to be announced at 12:35 p.m. Saturday.