Cycling in Copenhagen is – as with most cycling in Denmark – an important mode of transportation and a dominating feature of the cityscape, often noticed by visitors. The city offers a variety of favourable cycling conditions — dense urban proximities, short distances and flat terrain — along with an extensive and well-designed system of cycle tracks. This has earned it a reputation as one of the most bicycle-friendly cities in the world. Every day 1.2 million kilometres (0.75 million miles) are cycled in Copenhagen, with 62% of all inhabitants commuting to work, school, or university by bicycle; in fact, almost as many people commute by bicycle in greater Copenhagen as do those cycle to work in the entire United States. Cycling is generally perceived as a healthier, more environmentally friendly, cheaper, and often quicker way to get around town than by using an automobile.

Bicycles became common in Copenhagen at the beginning of the twentieth century. The city's first bicycle path was established on Esplanaden in 1892, another early example are the paths established around The Lakes in 1910, when the existing bridle paths were converted into isolated cycleways to accommodate the heavy growth in cycling at the time. In 1890 there were 2,500 bicycles in the city, just 17 years later that figure had increased to 80,000. In the 1920s and 1930s the popularity increased even further. As a spectator sport, six-day racing became popular in the 1930s. The first race was held in 1934 in the original Forum Copenhagen and its popularity peaked in the 1960s. During World War II, petrol was strictly rationed, making cycling the dominant form of transportation in Copenhagen. Also during the 1940s, the first recreational bicycle routes were developed through green spaces in the periphery of the municipality.

Starting in the 1950s, Copenhagen experienced a decline in utility cycling due to increasing wealth and affordability of motor vehicles. While no bike paths were actually removed at the time, new road construction omitted bicycle infrastructure, and many bike lanes were curtailed at intersections to increase the throughput of cars by adding turn lanes and other car related infrastructure in its place. At the same time car traffic increased dramatically on existing streets without bicycle infrastructure, decreasing the cyclists sense of safety on those streets. During the late 1960s and early 1970s the modal share of bicycles fell to an all-time low of 10%.

With the energy crisis, which hit Denmark harder than most countries, and the growing environmental movement in the 1970s, cycling experienced a renaissance. The government was forced to introduce car-free Sundays to conserve oil reserves. Many city dwellers thought it was the best day of the week, and the Danish Cyclists Federation, which had been on life support for years, experienced a rapid and massive increase in membership during the 1970s and 1980s. Bolstered by the increasing membership and new enthusiastic younger grassroots, it organised massive demonstrations in Copenhagen and other major cities, demanding better infrastructure and safety for the city's cyclists. Another grassroots action cited for putting cycling infrastructure on the political agenda was operation "White Crosses" where white crosses were painted on the streets where a cyclist had been killed in traffic. These events came at the same time as a number of planning reforms were initiated nationally, which gave individual residents the opportunity to have direct influence on new planning and zoning laws in their communities, and with that came a clear demand for segregated cycle paths.

Although the first separate cycle tracks were constructed much earlier, they did not become the norm until the early 1980s. As in many other cities planners suggested avoiding interference with car traffic on main roads, by using a "back streets strategy" of cycling routes on quiet residential streets, but uptake was low and the vast majority of cyclists refused to deviate from the more direct routes. Protests continued and on 4 June 1983 the Danish Cycling Federation, at a large bicycle demonstration, gave a "Cyclist Award" to Jens Kramer Mikkelsen in the form of a two-metre-long (6.6 ft) curb. Mikkelsen was the head of the traffic department and later lord mayor. The curb was placed on the bike lane on Amagerbrogade at the corner of Hollænderdybet. The gift was a symbol of the bicycle federations desire to have segregated bicycle facilities build on direct corridors, which happened to be along major streets, in order to make bicycle journeys competitive in time and effort. Politicians, although not very eager, gradually took up building cycle tracks on main roads and also began to develop the first coordinated strategies for increasing cycling in the municipality.

Since 1995, when the city started its monitoring system, cycling has constantly risen, reaching 41% by 2004 and 50% by 2010 for people living within the city of Copenhagen. In the 18 municipalities that make up the Copenhagen metropolitan region (Hovedstadsområdet) an area of approximately 350 square kilometres (140 sq mi) and a population of 1,2 million, 21% of all trips were done on bicycle by 2011. During the same period, from the 1980s until today, the network of cycle tracks and paths within the city of Copenhagen has almost doubled in length reaching 397 kilometres (247 mi) in 2010

The city of Copenhagen released its first bicycle report in 1996, where the city for the first time began measuring 10 key indicators, chosen by the city's traffic department and a group of regular cyclists. Aside from factual information like the budget allocated to cycling infrastructure, the length of the bicycle network, modal share and the number of cyclists and accident statistics, it also contains surveys asking regular cyclists for their opinion on the infrastructure, maintenance, and their perceived sense of safety. It gives residents an overview of the city's plans for cycling and, in later renditions, changes initiated since the previous account's publication. The city of Copenhagen has since released its bicycle report biennially, greatly increasing its scope in later editions.

In the municipal development plan from 1997, the city introduced a new concept of green bicycle routes, envisioned to be a coherent network of cycle routes that, to the extent possible, would be off-street routes through parks and other open green areas or, where that is not possible, to a limited extent along quiet streets with low traffic volumes. These routes were intended to supplement the existing network centred around busy corridors with high volume vehicle traffic. In 2000 the city released a proposal for a network of 22 green bicycle routes with a total length of 110 kilometres (68 mi) at a total estimated cost of 500 million DKK. As of 2012 around 40 km of network has been completed and the city is committed to completing the network in the coming years. The city hopes that the recreational and enhanced safety qualities of this network will attract certain groups of the population that currently use cars on trips to and from work, especially those with a 5–10 km commute.