The ruling Friday blocked the city's longstanding efforts to keep the referendum off ballots, The Detroit News reported.
If passed by voters in the Aug. 7 primary election, the referendum would pave the way for the legalized possession of and use of up to one ounce of marijuana on private property by those 21 and older, said Tim Beck, who heads the referendum group Coalition for a Safer Detroit.
"A long trail of voter abuse by the City of Detroit has come to an end," said Beck, 60, in an e-mail to supporters. "We got everything right. Our petitions were flawless."
In 2010, the Detroit City Council blocked the referendum from city ballots in a 3-0 vote, sparking a long legal battle between the city and marijuana advocates.
In February, the state Court of Appeals rejected the City Council's decision and said the ballot question should be allowed. The city appealed that ruling and took the dispute to the state Supreme Court.
Marijuana supporters, including those who use the drug as medicine, praised Friday's decision.
"Anything that keeps law enforcement away from patients and caregivers is good," said Steven Greene, host of the weekly Medical Marijuana Radio Show on WDTW-AM.
Detroit police spokeswoman Sgt. Eren Stephens said that the department would adapt to legalization "if it's handled in an appropriate way, and this is what the citizens of Detroit choose."