Alaattin Baydar (1901 – 13 July 1990) was a Turkish football player, who played for Fenerbahçe.
Born in Istanbul, he played as a right winger and right forward and was called Alâ.
He was the younger brother of Nasuhi Baydar, who was a founding member of Fenerbahçe.He played 18 years for Fenerbahçe between 1916-34.
He is ranked third in Fenerbahçe history with 362 goals in 324 matches, he also scored 24 goals in 39 matches against Galatasaray.
He won the 1920–21, 1922-23 Istanbul League Championships as a player, he furthermore won the 1963–64 and 1964-65 Turkish League Championships as a president.
He was a member of the General Harrington Cup squad.He was a member of the first Turkish national football team squad that played against Romania on 26 October 1923.
He played 16 times for the national team.
He was also a member of the national squads that competed in the 1924 and 1928 Summer Olympics.