No, you do not need an eTA if you are a permanent resident of Canada.
However, you must travel with a valid Permanent Resident Card or a Permanent Resident Travel Document. Otherwise, you may face delays or be prevented from boarding your flight to Canada.
If you do not currently have a Permanent Resident Card, find out how to apply.
If you are a Canadian permanent resident outside of Canada and do not have a Permanent Resident Card or your card is expired, find out how to apply for a Permanent Resident Travel Document.