Katajanokka's residents have included former Finnish President (from 1982 to 1994) Mauno Koivisto, composer Einojuhani Rautavaara and author-artist Tove Jansson.

The south side of Katajanokka is dominated by a passenger harbour which is frequented by large cruiseferries traveling between Helsinki, Stockholm, Mariehamn, Tallinn and Rostock.

The western part of the residential area, known as the "Old Side" of Katajanokka, is an upscale neighborhood and a well-preserved example of early 20th century Art Nouveau architecture, though up until the mid-19th century – while the centre of Helsinki was being filled with stone buildings – the area was essentially still a wooden shanty town.

A major part of the project was the conversion and extension of the old Russian naval barracks to house the Finnish foreign ministry.

During the development of Katajanokka in the 1970s and 1980s, many old red brick industrial buildings were spared by converting them for public uses, such as a primary school and an indoors sports arena.

This caused huge protests, and the demolition was put off for almost a decade, mainly because of opposition from local inhabitants, and the Green League party.

The organization publishes an annual regional magazine, Katajanokan kaiku (Finnish for "The Echo of Katajanokka").

The outskirts settlements formed on the peninsula remained mostly untouched for decades even after the rest of Helsinki had been completely rebuilt according to the zoning plan made by Johan Albrecht Ehrenström in the early 19th century.

[3] From the 1810s to the 1830s barracks buildings designed by Carl Ludvig Engel and Anders Fredrik Granstedt for the use of the Russian military were built on the eastern tip of Katajanokka.

The command of the Finnish Navy was located in a red brick building built in the 1880s until 1983 and the Guard Jaeger Regiment used the barracks in the 1960s.

[2]: 29–35 Rebuilding of a couple of houses destroyed in World War II or unbuilt lots has been done in accordance with the historical surroundings.

On the western side of Katajanokka is the Stora Enso headquarters designed by the academic Alvar Aalto (1962), a building clad in white marble, inspired by Italian renaissance palaces.

It is visible as an ending to the Pohjoisesplanadi street from the Market Square, although a distinctive feature of the building is that it sort of lacks a frontal facade.

The decorative red brick Norrmén house built in 1897 had been demolished to make room for Aalto's building.

There has been intense debate for several decades about whether Aalto's building fits in with the Market Square milieu and the cityscape dominated by the Uspenski Cathedral.

[2]: 45–46 In 1913 the so-called Chapel of Peace was built at the lot of the Uspenski Cathedral to commemorate the 100th anniversary of the Treaty of Fredrikshamn.

The zoning plan designed by the architectural trio Vilhelm Helander, Pekka Pakkala and Mikael Sundman was confirmed in 1977 and from 1977 to 1986 a total of 21 new apartment buildings were built in the area.

The zoning plan sought to return to the tightly-built urban space in a contrast to the earlier suburban type of construction, which has later been seen as a turning point in Finnish city design.

Car ferry traffic started on 9 July 1974 by the ship MS Viking 5 to Stockholm, Sweden.

[6] The site of the old harbour rail yard now hosts a wide avenue called Katajanokanlaituri, and many old warehouse buildings along it have been renovated into hotels and conference centres.

For a long time, the image of the northern shore of Katajanokka was dominated by large warehouses belonging to a freight forwarder.

The northern shore used to also host a garbage pier, where excrement was loaded into barges which took it to the countryside to act as fertiliser for the country fields.

[10] After the Valmet dock activity in Katajanokka had gradually moved to Vuosaari the old equipment pier was leased for the use of the icebreakers on 24 March 1975.

For example in summer 1971 an old system was kept in force, where two icebreakers were at Jätkäsaari, three at Hietalahti and three near the Valmet dock in Katajanokka.

In 2007 there was a plan for a hotel at the same site, named after Alvar Aalto and riding on his reputation, with the Swiss architecture bureau Herzog & de Meuron invited to design it.

In later versions the bridge was replaced with a tunnel, and a line going via Tervasaari and Sompasaari was found as an alternative route.