The arrests come after 14 raids in Halifax, Dartmouth and the surrounding communities of Porters Lake, Lawrencetown, Hammonds Plains and Cole Harbour.
The 11-month investigation led to the seizure of 20.5 kilograms of dried marijuana and 2,207 plants.
Chief Superintendent Brian Brennan called it a "joint operation" by 120 officers from the federal RCMP, RCMP in Nova Scotia, and Halifax and Truro police.
"Illegal marijuana grow operations harm our communities," he said Friday. "Wherever illegal marijuana grow operations exist, there's an increase in criminal activity and an associated increase in violence."
Police have not named the doctor, but the College of Physicians and Surgeons of Nova Scotia suspended Dr. Dinesh Sinha Friday in relation to the investigation.
Sinha was in the news in 2007 when his clinic was destroyed in a suspicious fire.
The Halifax Regional School Board confirmed that Tyler Rutledge, principal of St. Stephen's elementary school, is on administrative leave pending the results of the police investigation.
The board said the allegations against Rutledge are not tied to the school in any way.
Roger Stubbs, a midget AA hockey coach, and former Olympic paddler Mihai Apostol were also among the 29 arrested.
Selling marijuana prescriptions
Brennan said the arrested people were manipulating the medical marijuana legislation. "The doctor was basically selling the prescriptions to grow medical marijuana," he said. "The investigation into selling prescriptions to obtain medical marijuana licenses from Health Canada is on going."
The arrests were made Thursday morning, but police announced the raids Friday. Police expect to arrest at least one more person.
"Integrated Proceeds of Crime investigators are now reviewing the evidence gathered over the course of this significant and detailed investigation, which is still ongoing," said Brennan.
Twenty-eight of the 29 people arrested are scheduled to be in court March 13.
The grow operations were all indoors in homes, sheds and garages. Police said they were criminals acting in an organized manner, but not gang members.
RCMP released their own video of the sites on YouTube.