The actor, best known for playing Tommy Hyatt in the series, passed away on Tuesday at age 55.
“Philip was the endearing, loving boy, always willing and eager to connect with others,” Lavin, 83, told People magazine on Thursday.
“Although we were performing a show, the dynamic of creating that relationship made our connection very real and deep,” she continued. “He taught me how to be a good mom, just by being the wondrous boy he was.”
Lavin starred as a widowed mother and aspiring actress who worked as a waitress in Phoenix while raising her son, played by McKeon. The show ran for nine seasons.
McKeon’s spokesman Jeff Ballard told the outlet McKeon passed away in Texas after a battle with a long illness.
“We are all beyond heartbroken and devastated over Phil’s passing,” said Ballard. “His wonderful sense of humor, kindness and loyalty will be remembered by all who crossed his path in life.”’
After "Alice" ended, McKeon went on to star in a handful of other projects. His last on-screen appearance was 1994's "Ghoulies IV." He also directed a film and produced several others, including "Teresa's Tattoo," which starred his sister.
McKeon later worked in the news industry and hosted a radio show in Wimberley, Texas, close to his family.
Fox News’ Nate Day contributed to this report.