good question ny mafia i'll take a stab at it.

montreal
1. leonardo rizzuto/ stefano sollecito (rizzuto-sollecito clan)
- these 2 remain co-leaders of the most powerful clan in montreal and possibly all of canada.

2. vittorio mirarchi (mirarchi clan)
- a close second behind the 2 above in my opinion and considered by some to be a possible candidate to one day unite all of mtl under one leader.

-as far as montreal goes there is no one else with more power and influence than these 3. any other mafia members of any significance work under them...ex being marco pizzi, davide barberio, pietro d'adamo.

hamilton ( buffalo crime family)
1. domenico violi
- still considered the UB of the buffalo crime family as far as i know. currently released from short prison sentence and back on the street, only canadian to hold an admin position in an american based crime family.

2. rocco luppino
- although he has stayed below the radar for decades it is believed he may have held down the street for domenico during his imprisonment along with his remaining brothers; natale, john, antonio. all 4 are also uncles to domenico.

3. antonio iavarone
- considered for years now a top player in hamilton/ontario with links into ny.

toronto
1. cosimo commisso (siderno group)
- long considered the most powerful and respected 'ndrangheta leader in toronto. has recently beat legal cases in past few years.

2. angelo figliomeni Figliomeni 'ndrine?)
- was leader of large sports gambling and money laundering network busted in 2019. as has become common in canada that case fell apart because of opp and rcmp incompetence. operates separate of the siderno group.

3. vincenzo tavernese (aquino-coluccio/marina di gioisa ionica 'ndrine)
- related to both aquino and coluccio families, currently still in toronto and possible there rep in canada.

4. vincenzo demaria (siderno group?)
- the enigma???, is he the most powerful boss in ontario? is he the leader of his own 'ndrine or the siderno group or just a member? i have no idea to be honest and have never been able to get clarification on his status. i find it hard to believe that for someone who is being watched as much, imprisoned as much and in front of the courts as much as demaria that he would even have the time to be running a large sophisticated 'ndine/ crime family. i know there is a thread on demaria but even the most recent articles do no shed light on him. lastly if he was such a high level boss how is it then that the canadian gov't cannot prove as such to have him deported? then again we are talking canada here soooooo...???

there is my best attempt to show overall power in ontario and quebec. to my knowledge there is no other known mafia operations of any kind going on currently anywhere outside of these 2 provinces. everything appears to operate in the ontario to quebec corridor with some overlap into upstate new york both from the niagara falls border area and those municipalities in eastern quebec to the almost non existent "border" at cornwall,ontario/ akwesasne reserve.