Maj Gen Alenka Ermenc will take up the post of chief of staff on Wednesday.
The 55-year-old former army commander began her military career in 1991, when the country won its independence from the former Yugoslavia.
Maj Gen Ermenc is currently serving as the army’s deputy-chief of staff. President Borut Pahor said he hoped she would improve the army’s performance.
“The global trend of a deteriorating security situation continues and even though Slovenia is not directly threatened military-wise, it must improve its military safety relatively quickly,” he said in a statement released by his office.
Earlier this year, a Slovenian army brigade failed a Nato combat readiness test.
Maj Gen Ermenc graduated from the Royal College of Defence Studies in London and completed a Master’s degree in International Studies at London’s King’s College University.
She will replace Maj Gen Alan Geder, who has been in post since February.