Am I allowed to carry hiking poles / walking sticks into the airplane cabin with me?

Here we go - answer to a truly Frequently-Asked Question...

1. Aviation security policies are set by national authorities and they generally often state that hiking poles are not allowed in the cabin (carry-on bags), but they are allowed in checked baggage. Airlines follow and communicate these policies.
2. The airlines do not make the final decision on your poles. The airport security staff do. For airports in the USA, TSA states that "The final decision rests with the TSA officer on whether an item is allowed through the checkpoint." It is generally not useful or advisable to argue with the airport security staff. At Canadian airports, per the responsible authority, CATSA, hiking sticks/poles are permitted in carry-on luggage, provided they don't have sharp ends longer than 6 cm. See this website updated 2023-11-17.
3. There appears to be some variation in practice. For example, particularly in the US and Canada, many pilgrims report having no trouble carrying folding poles into the cabin with them. However, we have never had an authoritative explanation of why or when.
4. People needing mobility aids are generally allowed to take their mobility devices with them.
5. If you take your poles to security, in hopes of carrying them on board, you should be prepared to have them refused. Then, you will need to abandon them (they are not actually "confiscated") or you will need to go back to the check-in desk and send your poles as checked baggage. You should have a suitable bag or packaging to do that, and you must allow lots of time! You will need to go through security again.
6. Many pilgrims like to carry their precious backpacks and important items on board the plane. They often send a secondary bag/box as checked luggage, containing poles, liquids, sharp items, and other easy-to-replace items. This should reduce the hassle that would be created by a lost/delayed backpack with all your gear. Whatever bag/package you send will be subject to the luggage fees associated with your airline and ticket.
7. Airports in Spain might be more consistent than some places in refusing poles in cabin baggage. Specifically, on leaving Santiago, the rule is very strictly applied - you will certainly not be allowed to carry poles into the cabin. However, all most airlines will check your poles for free from Santiago.

[Edited 2023-07-16: Two words changed - one in point 1 and another in point 7.]
[Edited 2023-08-24: Last sentence deleted, since recent reports indicate that this policy is no longer in place and airlines are charging for checked poles.]
[Edited 2024-02-18: Added link to CATSA (Canada) website in point 2 above.]

To supplement the above post, here are some links to the guidance provided by governments of Australia, Canada, UK, and USA, specifically about walking poles:

Australia:
https://dangerousgoodsapp.casa.gov.au/ (a search term, like poles, needs to be entered)

Canada:
https://www.catsa-acsta.gc.ca/en/about-us. (This link was updated on forum on 2024-02-18.)

United Kingdom:
United States:
https://www.tsa.gov/travel/security-screening/whatcanibring/items/hiking-poles.
Note that only the US/TSA site points out that the officer conducting the security screening has flexibility.

I have updated the first post with respect to Canadian airports, and included a link to the current statement from CATSA. Walking sticks/poles are officially allowed by the Canadian security authority. Of course, the screening officers still have discretion to allow/disallow anything, and the airlines may have separate requirements.

If you have official updates to the regulations in other countries, feel free to send them to me by private Conversation, and I will add them.