Dunaújváros (Dunapentele, 1951–1961 Sztálinváros) is a Hungarian city in Central Transdanubia, along the Danube river. It is in Fejér county. Dunaújváros is one of the newest cities of the country. It was built in the 1950s during the industrialization of the country under Socialist rule, as a new city next to an already existing village, Dunapentele.

After the Second World War the new, Communist government started a major industrialisation programme, in support of its rearmament efforts. In 1949 Dunaújváros was chosen as site of the largest iron and steel works. Originally they were to be built close to Mohács, but the Hungarian-Yugoslavian relations worsened, and this new site was chosen, farther away from the Yugoslav border. The city was designed to have 25.000 residents.

The construction of the city began on May 2, 1950 near Dunapentele. Within one year more than 1000 housing units were built and the factory complex was under construction. The city took the name of Stalin officially on April 4, 1952; its name was Sztálinváros, "Stalin City" as a parallel to Stalingrad in the USSR. The metal works were opened by 1954. The city had a population of 27,772 at this time; 85% of them lived in nice, comfortable apartments, while about 4,200 people still lived in uncomfortable barracks which originally provided "homes" for the construction workers.

In the middle of the 1950s, public transport was organized, buses carrying 24,000 passengers each day. During the 1950s many cultural and sports facilities were built, the Endre Ságvári Primary School being the largest school in Central Europe in the 1960s.

In 1956, the construction was hindered by an earthquake and a flood, and in October by the start of the 1956 Hungarian Revolution. During the revolution the city used its historical name Dunapentele again. The Rákóczi radio station, which was created by the revolutionaries, was broadcasting from Dunapentele (in fact from a bus that was constantly moving around in the city so that it couldn't be located.) Even though the citizens of Dunapentele tried to defend their city, the Soviet army occupied the city on November 7, 1956. The city fell under martial law, Russian tanks were standing everywhere.

After the revolution the city was still the "trademark city" of socialism in Hungary, and was presented as such to foreign visitors. Among the visitors were Yuri Gagarin and the Indonesian president Sukarno. The city also provided scenery to popular movies.

In 1960, the ten-year-old city already had 31,000 residents to celebrate its anniversary.

On November 26, 1961 the city's name was changed to Dunaújváros (Duna|új|város meaning Danube-new-city; "New City upon Danube". ) as a consequence of Stalin's death (1953) and the Hungarian Revolution (1956).

The DUNAFERR factory complex is still is a determinant enterprise in the Hungarian steel industry, and a major employer in the area.

Today "New Danube City" is home to many new infrastructures (Pentele Bridge, direct highway link between Budapest and Dunaújváros) and the new South Korean Hankook factory, Europe's biggest tire factory of Hankook. This and other projects make Dunaújváros a new Hungarian boomtown.