The 49-year-old has been at the center of a stand-off with the state that has lasted more than two years and sparked several episodes of deadly unrest.
Sonko had submitted his candidacy with the constitutional council to contest the February election -- despite the state's refusal to provide him with the necessary documents.
Authorities said Saturday's meeting was banned due to "threats of disturbance to public order, hindrance to the free movement of people and goods and risk of infiltration by ill-intentioned people," according to a decree seen by AFP. It was signed by Dakar prefect Cherif Mouhamadou Blondin Ndiaye, who confirmed its authenticity.
"This is just another provocation, but we invite our comrades and supporters to stay tuned," El Malick Ndiaye, a spokesman for Sonko's dissolved party Pastef, said on Facebook.
Authorities ordered that Pastef be disbanded in July.
The party's back-up candidate Bassirou Diomaye Faye, who is also in prison, has also filed to run in February's presidential election.
Although the state refused to provide Sonko with the necessary documents to run for election, his lawyers said they had filed anyway, hoping the justice system would be more receptive.
Sonko's candidacy was filed on December 12, lawyer Cire Cledor Ly said in a statement sent to AFP late Friday.
"Mr Ousmane Sonko has fulfilled all the obligations imposed on him by the constitution, the electoral law, the regulations and the ministerial decrees. The state of Senegal has committed unimaginable acts to hinder submission of the candidacy application," Ly said.
Sonko was struck off Senegal's electoral register after being sentenced in June to two years' imprisonment for morally corrupting a young person.
He has been jailed since the end of July on other charges, including calling for insurrection, conspiracy with terrorist groups, and endangering state security.
He has denied the charges, saying they are intended to prevent him from running in the February 25 election.
President Macky Sall, who was elected in 2012 and re-elected in 2019, in July announced that he would not seek a third term. He handpicked his prime minister, Amadou Ba, as his coalition's presidential candidate.
In mid-December, a judge ordered that Sonko be re-installed on the list of candidates, confirming a lower court order that had been overturned on first appeal. The state has lodged an appeal against the decision.
More than 90 candidates have put their names forward to the Constitutional Council, which is due to announce the list of presidential contenders on January 20.