Mūrniece also served as parliamentary speaker during the 12th Saeima.
The other candidate for the post was Dagmāra Beitnere-Le Galla from the New Conservative Party.
44 MPs supported Murniece's candidacy, while 32 supported Beitnere-Le Galla.
Mūrniece thanked MPs for their support and emphasized that she will continue fulfilling her duties with her best conscience.
Before becoming an MP in the 11th Saeima, Mūrniece spent 16 years working as a journalist in the Latvijas Avīze newspaper where she covered domestic and foreign politics.
A translator by education, she has studied at the University of Latvia and the University of Economics and Culture.
The Saeima Speaker is an official who represents the Saeima and also acts as the interim president should he or she be abroad or sick.