Apostolos Kosmopoulos was a Greek athlete, sports official and Mayor of Thessaloniki.
Kosmopoulos was a member of the Philomousoi Club and participated, in 1905, in the first ever football match held in Thessaloniki. In 1908, he helped found Iraklis FC.
After his playing days were over, Kosmopoulos took an interest in the administrative affairs of Iraklis and served as President between 1920 and 1945 except for a two-year period.
He served as Mayor of Thessaloniki briefly in 1929 and also in the period of 1933 - 1934.
In 1931 he was honoured by Iraklis for 25 years of continuous service to the club. In 1936, he was honoured by SEGAS and, in 1939, by King George II.
He was the father of Thessaloniki mayor Dinos Kosmopoulos.