Protesters gathered outside the statehouse, The Atlanta Journal-Constitution reported. The bill, which takes effect July 1, is almost certain to face challenges in court.
"While I believe immigration is an issue that ... should be addressed at the federal level, this legislation I believe is a responsible step forward in the absence of federal action," Deal said at a news conference.
HB 87 allows police to check on whether some suspects are in the country legally, requires employers to check on the status of those they hire and makes transporting illegal immigrants a state crime. Utah has adopted a similar law.
A federal judge suspended enforcement of parts of the Arizona law. Deal said he believes the Georgia legislature crafted a bill that will pass muster in the courts.
President Barack Obama has called the Georgia law a "mistake." Charles Kuck, an immigration lawyer, told the newspaper Friday he expects to stop the "unconstitutional" bill from taking effect.