copied from another post:
Knife laws are generally handled in Canada on a precinct by precinct basis (municipal bylaws)
the general response from the Toronto precincts i contacted were, 3-4 inches will not be an issue, as long as you state its a tool not a weapon, and the cop BELIEVES you.
51st (tough neighborhood) said most knives on a younger person would likely be confiscated. however at 53rd (better neighborhood) the reponse was alot "nicer".
with a blade above 4 inches, the police will probably want to put you in handcuffs to talk to you for their safety (not arrested just detained) and will want a good reason why you are carrying that knife.
the police (i.e. the individual officer) in Canada have exceptional leeway when it comes to arresting people and each police officer will be different. With the wrong attitude a 1nch knife can land you in jail (seen it first hand). The police will always give the nod to those who are polite courteous and have the fore-site to come up with an answer before time:
What is the intended use of this weapon? (can't be defense)
Could that task be achieved with a smaller blade?
Do you mind if we take the blade and you can collect it from the precinct in the morning?
lastly if you plan on going to a bar, do not bring your EDC pocketknife, unless you have exceptional self control. if you get into a fight and are found with a knife, u go from being knee deep to neck deep in just a few seconds.
my edc is the kershaw leek G10 handle....a little expensive....BUT i do see the steel handeled leek on ebay for under $50 all the time and has the one handed opening feature you requested. i have been stopped carrying this knife in public when i was 16 but after a courteous minute with the officer, he let me keep the knife and sent me on my way.