The Estonian Radical Democratic Party (Estonian: Eesti Radikaal-Demokraatlik Erakond, ERDE) was a political party in Estonia.
The party had its roots in the Tallinn Radicals, who had formed in the early 1900s around Konstantin Päts and his Teataja newspaper.
[1] By 1917 the group had coalesced into the Radical Democratic Party, which won four seats in the Estonian Provincial Assembly in 1917.
In the Provincial Assembly the party was a member of the Democratic Bloc alongside the Estonian Democratic Party and the Rural League.
A rightwards shift in the party in 1918 resulted in Päts leaving to join the Rural League, leaving Ado Birk as the most prominent party member.