Kampala metropolitan police spokesman Patrick Onyango told AFP that the party's MC, Elvis Francis Juuko, was arrested on Friday in his hideout in Mityana, about 60 kilometers west of Kampala.
"Juuko has been brought back to Kampala and is in police custody. He has been charged with rash and negligent acts," Onyango said.
He did not indicate when the suspect is likely to appear before a court.
Ten people, mainly children, were killed in a crush at the Freedom City mall as revelers pushed through a single exit to watch a midnight fireworks show.
Police accuse the MC of urging partygoers to go through a narrow passage from the concert hall to watch the fireworks, triggering the stampede.
Concert organizers had closed other exits to prevent revelers who had not paid from gaining access to the overcrowded venue inside the shopping mall.
Deputy police spokesman Like Owoyesigire told AFP that mall manager Charles Kabiito was picked up by investigators from his office on Sunday and was now in detention facing similar charges.
He said more suspects including the mall owner proprietor have been summoned to appear before the investigating team and that if they failed to comply they would be arrested.
The event's promoter, Abby Musinguzi, was last week charged with negligence causing death and remanded in custody.
Musinguzi, better known by his club name Abitex, is expected to appear in court on Tuesday for a bail hearing.
President Yoweri Museveni has ordered a speedy investigation into the crush and offered the families of the deceased five million Ugandan shillings ($1,340) to assist with funeral expenses.
Most of the victims were aged between 10 and 20, police said.