The Municipality has an area of 10,805 km² and a population, according to the 2011 count, of 74,192 inhabitants. It has a high street plan with many pedestrian streets and bicycle paths. It provides access to major motorways such as Attiki Odos, Kifisias Avenue, and Mesogeion Avenue and is served by Athens Metro and suburban stations Halandri, Doukissis Plakentias, and Nomismatokopeio. The municipality is found at an altitude of 185-230 meters and is adjacent to the municipalities of Marousi, Vrilissia, Psychiko, Agia Paraskevi and Papagou - Holargos.
Halandri, in the early 20th Century, was poor economically with few residents. In 1909, however, when the city plan was implemented and Kifisias developed as the main road, Halandri exhibited craft and commercial activity and acquired a reputation as a resort property for the Athenians. During the Asia Minor catastrophe, Halandri received several refugees, who are integrated into the existing population as well as the workforce. Until 1925, Halandri belonged administratively to Athens, but from then on gained its own autonomy and became a community. The period from 1925 to 1940 found the suburb acquiring infrastructure, electricity, and water supply. In the dark years of the war, it - like the rest of Greece - sank into the German occupation and lived through famine and executions of personalities such as Manos and Vlavianos, by the Nazi regime - now buried in the Pikermi Tomb.
In 1945, Halandri was declared a Municipality and since then has been characterized by both population and business growth. It has a shopping center with a wealth of businesses, gathering a market audience from all the northern regions of Attica. The suburb is still known for the personalities born or living there. To name a few: Kostas Voutsas (actor), Elena Nathanael (actor), Charilaos Florakis (general secretary of KKE), Notis Mavroudis (composer-musician), Euripides (ancient writer), and Themistoklis (ancient politician and military).