In some countries, a Senior Advisor is an appointed position by the Head of State to advise on the highest levels of national and government policy. Sometimes a junior position to this is called a National Policy Advisor. In some instances, these advisors form a Council of State or a State Council. Senior Advisor also is a title for senior civil servants in several countries, and is also used in organisations.
Taiwan (Republic of China)
The President of the Republic of China can appoint Senior Advisors to the Office of the President of the Republic of China (中華民國總統府資政) and National Policy Advisors to the Office of the President of the Republic of China (中華民國總統府國策顧問), but they do not form a council.