Lydia Emilie Florence Jannsen (b. Fennern, Livonia, 1843 – d. 1886, Kronstadt, Russia) was an Estonian poet. Nicknamed Lydia of the Dawn, her poems were either anonymous or signed Lydia Koidula. In 1873 she married Eduard Michelson from Livonia and moved to Russia. She was a renowned poetess, to whom the founding of Estonian theatre is attributed.
