Flensburg is the most northerly city in Germany, located directly on the border with Denmark. It is the third largest city in Schleswig-Holstein after Kiel and Lübeck. On the north-south axis, Flensburg is connected to Kiel and Hamburg to the south and Aarhus (Denmark) to the north via motorway 7.

Flensburg harbour, which was also an important naval base until the 1990s, is gradually declining in importance as an industrial port, which is why the eastern side of the harbour is to be developed into a mixed-use urban quarter. However, it is gaining relevance as a tourist and leisure harbour. Flensburg is also home to the Mürwik Naval Academy, which is responsible for the Gorch Fock sailing training ship, among other things.

The D-city Flensburg has 96,431 inhabitants.

The population development in Flensburg shows a positive dynamic. Between 2018 and 2023, the number of inhabitants increased by 3.5% according to the update of the 2011 census, making Flensburg one of the fastest-growing D-cities. The 2022 census revealed a deviation of 2.66% from the projections based on the 2011 census. The forecast until 2040 indicates a further population growth of 4%, which is significantly above the average of D-cities.

In Flensburg, there are 53,424 households, with the proportion of single-person households at around 43%, placing it in the middle range among D-cities. By 2040, household growth of 6.6% is predicted, representing an above-average development compared to other D-cities. With a student population of approximately 9%, Flensburg has a significant academic presence that exceeds the average of D-cities.

Flensburg's demographic dynamics over the past five years are characterised by a slightly negative natural balance, which is more than offset by a moderately positive migration balance. Migration gains are the main driver of population growth. Regarding age structure, Flensburg shows comparatively low values for both the youth dependency ratio (28%) and the old-age dependency ratio (32%), indicating a strongly employment-oriented population structure. This structure is rather atypical for D-cities and is further reinforced by the above-average proportion of students.

Flensburg is distinguished by positive demographic development with above-average growth. The strongly employment-oriented population structure combined with the significant university presence forms a solid basis for future urban development. The projected positive development in terms of inhabitants and households suggests continued pressure on the housing market.

With 46,500 employees subject to social insurance contributions, Flensburg has an average-sized labour market among D-cities.

More than half of the employees in Flensburg, namely 53%, work in large companies. The sector structure shows a certain degree of diversification, with healthcare and social services accounting for the largest share at 20%, followed by manufacturing including construction (14%), wholesale and retail (13%) and public administration (11%). This distribution largely corresponds to a classic sector structure for D-cities.

The labour market dynamics in Flensburg have been above average in recent years. With employment growth of 5.5% over the last five years, the city is in the top third of all RIWIS cities and shows a robust development. The positive commuter balance of around 11,100 is concentrated regionally in the immediate neighbouring municipalities.

With an unemployment rate of 8.3%, the quality of the labour market in Flensburg is average compared to other D-cities. However, the development over the last five years shows an atypical trend with a slight increase of 0.3 percentage points, as Flensburg is one of the cities with the least favourable development among all RIWIS cities.

As a regional centre, Flensburg performs a central supply function that extends beyond the city limits and also includes the neighbouring municipalities in Denmark. With a centrality index of 160.8, the city is one of the most important retail locations among the D-cities.

At 86.8, the purchasing power index is below the average for comparable cities, which points to economic structural challenges and could limit local consumption opportunities. Nevertheless, demand for retail space remains stable, particularly in the prime locations of Holm and Südermarkt, where the prime rent is EUR 63/sqm. This puts Flensburg in the top third of D-cities.

The yield for central locations is 5.6 % and is in the lower third of all RIWIS cities. This indicates comparatively high purchase prices and solid investment demand. Overall, Flensburg combines a strong retail centrality with moderate purchasing power, which makes the location attractive for retailers, even if the market environment is more stable than dynamic.