Dean of the United States Senate

The Dean of the United States Senate is the Senator that has been in office the longest.
Unlike the office of President pro tem, the Office of Dean is not an official position.
History.
After the death of Daniel Inouye on December 17, 2012, Patrick Leahy became the new Dean of the Senate. Also since the death of Inouye, Leahy became the President pro tempore and "dean". Leahy is the senorist Democratic Senate politician in the United States. When Leahy retired, Chuck Grassley assumed the role in 2023.