Daniel Ray "Dan" Coats (born May 16, 1943) is an American (United States) lawyer, politician, lobbyist, and diplomat. A member of the Republican Party (United States Republican Party), he served as a United States Senator (United States Senate) from Indiana from 1989 to 1999. Coats was appointed to fill the seat vacated by Dan Quayle following his election (United States presidential election, 1988) as Vice President of the United States in 1988. He won the 1990 special election (United States Senate special election in Indiana, 1990) to serve the remainder of Quayles unexpired term, as well as the 1992 election (United States Senate election in Indiana, 1992) for his own full six-year term. He did not seek re-election in 1998 (United States Senate election in Indiana, 1998).

Prior to his service in the U.S. Senate, Coats was a member of the United States House of Representatives, representing Indianas 4th congressional district from 1981 to 1989. After retiring from the Senate Coats served as U.S. Ambassador to Germany (United States Ambassador to Germany) from 2001 to 2005.

After serving as Ambassador, Coats moved to Virginia as a senior Lobbyist and policy adviser at King & Spaldings Washington DC offices serving large corporate concerns and banking interests.

On February 10, 2010, Coats announced that he would relocate to Indiana to seek the US Senate seat held by Evan Bayh in the 2010 U.S. Senate election (United States Senate election in Indiana, 2010). On February 15, Bayh revealed that he will not be running for reelection. Coats was selected as the Republican nominee in the May 4, 2010 Indiana primary.