It is the economic and cultural centre of the traditional region of Lower Carniola (southeastern Slovenia) and the seat of the City Municipality of Novo Mesto.

[3] Following World War I and the dissolution of Austria-Hungary, the city became part of the Kingdom of Yugoslavia and was officially renamed Novo mesto.

During World War II, the city was controlled by Fascist Italy as part of the Province of Ljubljana until Mussolini's downfall in 1943.

[7] In 1958, the authorities of the Socialist Federal Republic of Yugoslavia had a motorway built connecting the Slovenian capital Ljubljana and Zagreb in Croatia, which passed through Novo Mesto.

Lying in partial rain shadow, precipitation is much lower than just 20 km (12 mi) to the west, and foehn winds blowing from southwest over the Dinaric alps can bring very warm weather in any month of the year.

The turning point is the September 1920 exhibition named Novo Mesto Spring, which brought together artists of different genres and marks the beginning of avant-garde art in Slovenia.

A significant part in the musical development of the town was contributed by students and the teaching staff of the Novo Mesto Grammar School.

In the 20th century, particularly after World War II, a number of influential contemporary (jazz, rock, and pop) music groups appeared and created in the town, the most notable of them being Rudolfovo [sl], Dan D and others.

In the early 21st century, the most popular pop-rock music group was Dan D, whereas classical music gained two important pieces of work in the frame of the George Slatkonia Vocal Academy, a chamber opera (The Baptism on the Savica) and Te Deum, a monumental cantata work.

Trdina, after whom the central cultural venue of the town is named Janez Trdina Cultural Centre, lived in Novo Mesto in exile and wrote primarily short fictional stories about the Gorjanci hill range, which he published under the title Fairytales and Stories about Gorjanci (Bajke in povesti o Gorjancih).

Kette, who lived in Novo Mesto in the time of his studies, wrote lyrical poetry, particularly dedicated to Angela Smola whom he met in the town's chapter church.

Novo Mesto Cathedral, standing on Kapitelj Hill above the town, is dedicated to Saint Nicholas and is an originally Gothic building that was rebuilt in the Baroque style in the 17th century.