Common Mistakes and Confusing Words in English
Councillor is a noun which means an elected member of a local government.
For example: "He was elected to be a councillor in 1998."
Counsellor is a noun, which means someone who is trained to listen to people and give them advice about their problems.
For example: "The student union now employs a counsellor to help students with both personal and work-related problems."
Thanks to Daniel Hugo