The London County Council (LCC) was the principal local government body for the County of London throughout its existence from 1889 to 1965, and the first London-wide general municipal authority to be directly elected. It covered the area today known as Inner London and was replaced by the Greater London Council. The LCC was the largest, most significant and most ambitious English municipal authority of its day.

By the 19th century, the City of London Corporation covered only a small fraction of the metropolis. From 1855, the Metropolitan Board of Works (MBW) had certain powers across what is now Inner London, but it was appointed rather than elected. Many powers remained in the hands of traditional bodies such as parishes and the counties of Middlesex, Surrey, and Kent. The Local Government Act 1888 created a new County of London, with effect from 1889, and the English county councils, of which LCC was one. This followed a succession of scandals involving the MBW - which was abolished on LCC's creation - and was also prompted by a general desire to create a competent government for the metropolitan area, capable of delivering strategic services effectively. The Conservative government of the day would have preferred not to create a single body covering the whole of the new County of London, but its electoral pact with the Liberal Unionists led it to this policy. LCC was established as a provisional council on 31 January 1889 and came into its powers on 21 March 1889.

In the first elections to the LCC, in January 1889, the Progressive Party, closely allied to the Liberal Party, won seventy of the 118 seats. It lost power in 1907 to the Municipal Reform Party (a Conservative organisation) under Richard Robinson.

The LCC provided very few services within the ancient City of London, where the existing Corporation had a near-monopoly of local governance. Shortly after its creation, a Royal Commission on the Amalgamation of the City and County of London considered the means for amalgamating the two. Although this was not achieved, it led to the creation of 28 metropolitan boroughs as lower tier authorities, replacing the various local vestries and boards in 1900; these boroughs also assumed some powers of the LCC and shared others.

The LCC inherited the powers of its predecessor the MBW, but had wider authority over matters such as education, city planning and council housing. It took over the functions of the London School Board in 1903, and Dr C W Kimmins was appointed chief inspector of the education department in 1904.

From 1899, the Council progressively acquired and operated the tramways in the county, which it electrified from 1903. By 1933, when the LCC Tramways were taken over by the London Passenger Transport Board, it was the largest tram operator in the United Kingdom, with more than 167 miles (269 km) of route and over 1,700 tramcars.

Under the Local Government Act 1929, the LCC assumed responsibility on 1st April 1930 for the Poor Law Boards of Guardians' general hospitals and the Metropolitan Asylums Board's hospitals for infectious diseases , the mentally disordered and feeble minded, children's hospitals, pathology laboratories and ambulance stations.

One of the LCC's most important roles during the late 19th and early 20th century, was in the management of the expanding city and the re-development of its growing slums. In the Victorian era, new housing had been intentionally urban and large-scale tenement buildings dominated. Beginning in the 1930s, the LCC incentivised an increase in more suburban housing styles. A less-dense style of development, focusing on single family homes, was popular among London housing developers because it was believed that this would satisfy the working classes and provide insurance, "against Bolshevism," to quote one parliamentary secretary. The LCC set the standard for new construction at 12 houses per acre of land at a time when some London areas had as many as 80 housing units per acre. The passage of the Housing of the Working Classes Act in 1885 gave the LCC the power to compel the sale of land for housing development, a power that was vital to the systematic rehousing that began under the council's early Progressive Party leadership.