An immigration judge ruled on Tuesday that Abd al-Jabbar Hamdan, 44, should have known that his work for the Holy Land Foundation for Relief and Development provided support to the group.
"Our laws prohibit aliens who are living here as our guests to use this country as a base to advocate terrorism or raise money for terrorist causes," said John Salter, Los Angeles chief counsel for the US Immigration and Customs Enforcement.
The judge did not name the country where Hamdan would be deported to.
Hamdan, of Buena Park, was arrested on immigration violations in July as federal authorities unsealed an indictment against the Texas-based charity, charging it with funnelling millions of dollars to Hamas.
He was not charged in that case but was charged with living in the US without a valid visa and jailed without bail.
Hamdan, a founder of an Anaheim mosque who was born in a Palestinian refugee camp in the West Bank, admitted to acting as a fundraiser for Holy Land, but said he believed the donations were used only for humanitarian projects.