Leopold (Leo) Henrik Stanislaus Mechelin (24 November 1839 in Hamina, Finland – 26 January 1914 in Helsinki, Finland) was a Finnish professor, statesman, senator, liberal reformer and businessman.
A leading defender of the autonomy of the Grand Duchy of Finland, and of the rights of women and minorities, Mechelin's 1905–1908 government
("Mechelin's Senate") made Finland the first nation in the world with the universal right to vote and to be elected.
During his period in office the freedom of expression, the press, and of assembly were introduced.