Lubbock was educated at Eton College from 1845 and afterwards was taken into his father's bank (which later amalgamated with Coutts & Co), where he became a partner at the age of twenty-two. In 1865 he succeeded to the baronetcy.
In 1870, and again in 1874, he was elected as a Liberal Party Member of Parliament (MP) for Maidstone. He lost the seat at the election of 1880; but was at once elected member for the University of London, of which he had been vice-chancellor since 1872. He carried numerous enactments in parliament, including the Bank Holidays Act of 1871 and the Ancient Monuments Act of 1882. When the Liberals split in 1886 over Irish Home Rule, Lubbock joined the breakaway Liberal Unionist Party.
Lubbock was elected the first president of the Institute of Bankers in 1879; in 1881 he was president of the British Association, and from 1881 to 1886 president of the Linnean Society of London. In March 1883 he founded the Bank Clerks Orphanage, which in 1986 became the Bankers Benevolent Fund - a charity for bank employees, past and present and their dependants. In January 1884 he founded the Proportional Representation Society, later to become the Electoral Reform Society.
In 1865 Lubbock published what was probably the most influential archaeological text book of the 19th Century, Pre-historic Times, as Illustrated by Ancient Remains, and the Manners and Customs of Modern Savages, and was responsible for inventing the names Palaeolithic and Neolithic to denote the Old and New Stone Ages respectively.
Lubbock was also an amateur biologist of some distinction, writing books on hymenoptera (Ants, Bees, and Wasps. A Record of Observations on the Habits of the Social Hymenoptera.New York: Appleton, 1884.), on insect sense organs and development, on the intelligence of animals, and on other natural history topics. He was a member of the famous X Club founded by T.H. Huxley to promote the growth of science in Britain. The Punch verse of 1882 captured him perfectly:
He carried out extensive correspondence with Charles Darwin, who was his neighbor in Downe except for a brief period 1861-1865, when Lubbock moved to Chislehurst. He first leased and then sold to Darwin the land on which the latter's famed Sand Walk was made. He helped engineer Darwin's burial in Westminster Abbey following the latter's death in 1882.
Lubbock received honorary degrees from the universities of Oxford, Cambridge (where he was Rede lecturer in 1886), Edinburgh, Dublin, and Wurzburg; and in 1878 was appointed a trustee of the British Museum. From 1888 to 1892 he was president of the London Chamber of Commerce; from 1889 to 1890 vice-chairman and from 1890 to 1892 chairman of the London County Council.
In February 1890 he was appointed a privy councillor; and was chairman of the committee of design on the new coinage in 1891. In January 1900 he was raised to the peerage, under the title of Baron Avebury.