Baldur Ragnarsson (25 August 1930 – 25 December 2018) was an Icelandic poet and author of Esperanto works.

Baldur learned Esperanto at school in 1949 and was active in the movement to promote the use of this language since 1952.

A Member of the Esperanto Academy since 1979, he was editor of the journal Norda Prismo from 1958 to 1974.

In 2007 the Association of Esperanto-speaking authors (Esperantlingva Verkista Asocio) nominated him as their candidate for the Nobel Prize in Literature following the death of William Auld in 2006.

He was also written two collections of Esperanto poems: Ŝtupoj sen nomo and Esploroj.