Li's message in front-page advertisements in major newspapers in the Asian financial hub urged the public to "cease the anger with love" and "stop the violence." The advertisements were signed "a Hong Kong citizen Li Ka-shing."
Ten weeks of confrontations between police and protesters have plunged Hong Kong into its worst crisis since it reverted from British to Chinese rule in 1997, and have presented the biggest popular challenge to Chinese President Xi Jingping since he came to power in 2012.
China has likened the increasingly violent protests to terrorism and warned it could use force to quell them, as US President Donald Trump urged Xi meet protesters to defuse the tension.
More mass demonstrations are expected through the weekend. Police tactics against protesters have been hardening and Li, 91, warned that "the best cause can lead to the worst results."
More than 700 people have been arrested since the protests began in June, and tear gas has frequently been used by police in attempts to disperse protests across the city.
A rally called "Stand with Hong Kong, Power to the People" is planned in the central business district on Friday night. That event has permission from authorities but police have banned other protests planned for the weekend.
A march planned for Sunday by the Civil Human Rights Front, which organized the million-strong marches in June, has only been allowed an assembly in Victoria Park on Hong Kong island because of safety concerns.
The group is appealing against the police decision.
Another march planned in Kowloon's Hung Hom district on Saturday has also been banned.
'UNINTENDED CONSEQUENCES'
Li, who formerly chaired CK Hutchison Holdings, did not make any reference to supporting the government or its embattled leader Carrie Lam in the advertisements, which encouraged freedom, tolerance and the rule of law.
However, a statement issued later by a spokesman quoted Li as saying "the road to Hell is often paved with good intentions. We need to be mindful of unintended consequences."
He said it was important to invest in the younger generation to bear fruit for the future and for Hong Kong.
"The young always fear the future has nothing to do with them," Li's statement said. "I think the government heard the messages from the protesters loud and clear and is diligently racking their brains now for solutions."
Many businesses, including other major property developers, have publicly backed Lam's administration and the city's police force.
Research firm Capital Economics warned on Thursday the protests could push Hong Kong into a recession, with a risk of capital flight. Hong Kong's property market, one of the world's most expensive, would be particularly hard hit, it said.
Lam sought in a Facebook post late on Thursday to clear up what she said was a misunderstanding about parts of a speech last week.
She had referred to protesters as having no stake in Hong Kong's society in comments that provoked a backlash and fueled further unrest. However, Lam said she meant to say "we all have a stake in Hong Kong."