Kalevipoeg is an epic poem by Friedrich Reinhold Kreutzwald held to be the Estonian national epic.

It was written by Friedrich Reinhold Kreutzwald on motives of Estonian folk-lore. The main material is taken from legends on a giant hero named Kalevipoeg ("Kalev's Son"). They mainly interpret various natural objects as traces of Kalevipoeg's deeds and have similarities with giant stories from neighbouring countries, including Scandinavia.

In Estonian legends (mainly from East Estonia) Kalevipoeg bears stones or throws them at enemies, and also uses planks as weapons, following advices of a hedgehog. He also forms surface structures on landscape and bodies of water and builds towns. He walks through deep water. Kalevipoeg dies since his feet are cut down.

In folk songs, Kalevipoeg occurs rarely.

In literature Kalevipoeg is first mentioned by Heinrich Stahl (17th century).

In 1839, Friedrich Robert Faehlmann read a paper at the Learned Estonian Society about the legends of Kalevipoeg. He sketched the plot of a national romantic epic poem.

In 1850, after Faehlmann's death, Kreutzwald started writing the poem, interpreting it as the reconstruction of an obsolete oral epic.

The first version of Kalevipoeg (1853; 13,817 verses) could not be printed because of the censorship. The second, thoroughly revised version (19,087 verses) was published in sequels as an academic publication by the Learned Estonian Society in 18571861. The publication included a translation into German. In 1862, the third, somewhat abridged version (19,023 verses) came out. This was a book for common readers. It was printed in Kuopio, Finland.

The epic uses the form of the old Estonian alliterative verse. Approximately one eighth of verses are authentic, the rest is imitation.