The court says it will hear the Etobicoke Centre case in an unusual summer sitting on July 10.
Last month, a lower court judge threw out the election result because of voting irregularities..
Conservative MP Ted Opitz, who won the seat by 26 votes, appealed that ruling to the Supreme Court, but had nothing to say today about the July hearing date.
Former Liberal MP Borys Wrzesnewskyj, who filed the original court case, says its good for democracy that the case will be heard quickly.
He says voters in the Toronto riding don't know who they elected.
"Technically, it appears we don't know who was elected in the last election, yet we have someone that continues to vote in the House of Commons," Wrzesnewskyj said.
"It's a very difficult situation and I am sure the electorate would want clarity."
Wrzesnewskyj said he has no idea how long it will take the court to produce a decision, but said it's a vital issue.
"This is about our democratic process, so it's clearly one of the most important issues that the Supreme Court is going to be looking at."
The Liberals have called for Opitz to step down,but he has vowed to continue doing his job as MP until the top court rules on the matter.
The Liberals call the appeal a stalling tactic, designed to allow Opitz to unfairly use his parliamentary resources to campaign for an eventual byelection.
Opitz originally argued that his lawyers needed more time to get ready.
"His legal team required two months to prepare documents, and then another month to respond to documents, so they needed three months," Wrzesnewskyj said.
"We are still trying to figure out on what basis, points of law or points of fact, that they were appealing — and we still don't know."
Only five other election results have been nullified by the courts since 1949. None of those rulings was appealed and byelections were quickly called in each riding.
Opitz said he appealed as a matter of principle:
"It is in the public interest that election results be respected and that voters not be disenfranchised," he said in a statement issued when he announced his appeal.
In a ruling last month, Judge Thomas Lederer of the Ontario Superior Court found that Elections Canada officials made clerical errors at the polls. He threw out 79 votes and overturned the final result.
The votes were cancelled because of improperly filled-out paperwork for voters left off the list of electors or who needed someone to vouch for their identity.
In his ruling, Lederer specifically stressed the irregularities were the result of clerical errors by well-meaning Elections Canada officials, not the product of fraud or intentional wrongdoing.