Deniz Baykal, Turkish lawyer and politician, Deputy Prime Minister of Turkey

Deniz Baykal (born 20 July 1938) is a Turkish politician at the Republican People's Party (Turkish: Cumhuriyet Halk Partisi, abbreviated CHP) who served as Deputy Prime Minister and Minister of Foreign Affairs from 1995 to 1996. Having served in numerous government positions, Baykal led the CHP from 1992 to February 1995, from September 1995 to 1999 and again from 2000 to 2010. Between 2002 and 2010, he also served as the Leader of the Opposition by virtue of leading the second largest party in Parliament.

First elected to Parliament in 1973, Baykal went on to serve as Minister of Finance in the CHP-MSP coalition of 1974 and as Minister of Energy and Natural Resources in the third government of Bülent Ecevit from 1978 to 1979. With the CHP shut down during the 1980 Turkish coup d'état, Baykal was briefly imprisoned before being elected to Parliament once again in 1987 from the new Social Democratic People's Party (SHP).

Baykal was one of the leading members of the re-established CHP, which was founded again in 1992. He served as the party's leader until 1995, when the CHP and SHP merged during a convention. He was re-elected leader in September 1995, after which Baykal contested the 1995 general election and formed a coalition government with Tansu Çiller's True Path Party. He served concurrently as Deputy Prime Minister and Minister of Foreign Affairs between 1995 and 1996. Leading the CHP into a landslide defeat in the 1999 general election, Baykal resigned after the party was entirely ejected from Parliament for failing to surpass the 10% election threshold. Regardless, he was re-elected as leader in 2000 and led the party to a moderate success in the 2002 general election, becoming the Leader of the Opposition. He resigned as leader in 2010 after the release of a video of Baykal's private relationship with another CHP MP.

As the oldest MP in Parliament following the June 2015 general election, Baykal briefly served as the interim Speaker of the Grand National Assembly. He was the CHP's candidate to become the permanent Parliamentary Speaker for the 25th Parliament of Turkey in the June–July 2015 speaker elections, but lost to Justice and Development Party candidate İsmet Yılmaz. Following a breakdown of coalition talks after the election, Baykal was offered a ministerial position in the subsequent interim election government formed by AKP leader Ahmet Davutoğlu, which he turned down in line with the party executive's decision. He became interim parliamentary Speaker for a second time on 17 November 2015 by virtue of being the oldest MP after the November 2015 general election. He was succeeded by the AKP MP İsmail Kahraman, who was elected Speaker on 22 November 2015.