Chiajna (Romanian pronunciation: [ˈkjaʒna]) is a commune in the south-west of Ilfov County, Muntenia, Romania, immediately west of the capital, Bucharest.

[2] In one version Chiajna was named after the wife of Cernica Știrbey, a Wallachian vornic who owned the area where people from Cernavodă settled and founded the village.

Another story says that Lady Chiajna (c. 1525–1588, Istanbul) was the daughter of Petru Rareș, the voievod of Moldavia, an illegitimate child of Ștefan cel Mare.

In Romanian literature (e.g., the novella Doamna Chiajna, published in 1860 by author Alexandru Odobescu), she is a famous and frightening female character, similar to Lady Macbeth.

Since the 2010s, Chiajna has been the site of new residential developments collectively known as "Militari Residence", which have become notorious for their poor urban planning and construction practices.