Johann Voldemar Jannsen was an Estonian journalist and poet, born in Vana-Vändra on 16 May 1819.

He wrote the words of the Estonian national anthem, Mu isamaa, mu õnn ja rõõm, and was the father of the poet Lydia Koidula. As the leader of the choral society which organized the first nationwide Song Festival in Tartu in 1869, Jannsen plaid a crucial role in the Estonian National Awakening .

He died in Tartu on 13 July 1890.