I am a Canadian citizen and a permanent resident of the US. Would I be allowed entry into Canada to visit my elderly and ailing father during COVID-19 border restrictions?
Of course you can go to Canada; they can't refuse a citizen entry, not even for a pandemic. You will need to be able to prove your Canadian citizenship, ideally with your Canadian passport. You will be required to self-isolate for 14 days or be assigned to a place where you will be quarantined, if you do not have a place to self-isolate.
It is important to note that, during this quarantine period, you may not have any contact with "vulnerable people, such as people 65 years or older, or people with underlying medical conditions."
You also need to bring your green card so that you can return to the US.
1It's actually not a given that Canadian citizens who are not resident in Canada will be allowed over the border. Some of the answers to the linked question indicate it may not be. And if you are allowed in it is far from certain you would be allowed back. Jun 3, 2020 at 18:15
@DJClayworth They're also out of date. Jun 3, 2020 at 18:34
3@DJClayworth could you link to a Canadian government regulation which explicitly bans non-resident Canadians?– JonathanReez ♦Jun 3, 2020 at 20:38
Indeed. The link above is to the current regulations, as of today. They'll change, of course, but the post describes today's situation. Jun 3, 2020 at 22:31
Links in the other answers. Several quotes that "nonessential travel is banned" but "Canadian citizens returning will beexempted. Jun 3, 2020 at 23:40