Belgium's top court on Wednesday threw out the actions on the grounds that none of the accused held Belgium nationality at the time the lawsuits were launched.
The Cour de Cassation rejected the suits for crimes against humanity filed under Belgium's so-called "universal competence" law.
The 1993 law originally allowed Belgian courts to rule on crimes against humanity regardless of the nationality of the perpetrator or where the crimes took place.
But under severe diplomatic pressure from Washington, the Belgian government agreed this year to scrap the law and in August parliament approved a new, watered-down version requiring that plaintiffs be Belgian nationals.
Sharon was named in a lawsuit alongside Israeli General Amos Yaron over massacres in 1982 of Palestinians at the Sabra and Shatila refugee camps in Lebanon.
Another case targeted US leaders at the time of the 1991 Gulf War, including former president Bush and current US Secretary of State Colin Powell.
Wednesday's court decision also threw out the legal suits against Powell and General Yaron.