Nadon's appointment has been in legal limbo since Prime Minister Stephen Harper named him to the post in September. His nomination was confirmed in October.
At issue, is whether Justice Nadon, a Quebec-born Federal Court judge, is qualified to represent Quebec on the top court's bench, even though he has not practised in Quebec for over two decades.
Toronto constitutional lawyer Rocco Galati and Quebec's attorney general have challenged Nadon's eligibility, putting into question the constitutionality of Harper's sixth appointment to the Supreme Court.
That forced the federal government to submit a reference to the Supreme Court about Nadon's appointment.
The Supreme Court Act requires the three judges from Quebec to be appointed from among the judges of the Court of Appeal or of the Superior Court of Quebec, or from among the advocates of that province.
Nadon, who grew up in Quebec and attended law school in the province, lives in Ottawa where he was appointed to the Federal Court by Prime Minister Jean Chrétien in 1993.
Anticipating debate over the nomination, the federal government sought a legal opinion on the Nadon appointment from three distinguished legal experts including retired Supreme Court Justice Ian Binnie, at a cost of more than $11,000.
The legal advice concluded that a sitting judge of the Federal Court is qualified for appointment to the Supreme Court as a Quebec member, if he or she practised law in Quebec for at least 10 years prior to becoming a judge.
The top court has been hearing cases by an even number of judges since October.
Friday's decision will come after the Supreme Court reserved its decision after hearing arguments for five hours on Jan. 15.