Arnold Koller is a Swiss professor and politician. He served as a member of the Federal Council from 1987 to 1999 for the Christian Democratic People's Party (CVP). Koller previously served as a member of the National Council from 1971 to 1986. He did also serve two terms of the as President of the Swiss Confederation in 1990 and 1997. He is primarily known for Lex Koller, a Swiss Federal Act on Acquisitions of Real Estate by Persons Abroad, which he initiated.