Sir Leo George Chiozza Money^{[needs English IPA]} (born Leone Giorgio Chiozza, Italian pronunciation: [leˈoːne ˈdʒordʒo ˈkjoddza]; 13 June 1870 – 25 September 1944) was an Italian-born economic theorist who moved to Britain in the 1890s, where he made his name as a politician, journalist and author. In the early years of the 20th century his views attracted the interest of two future Prime Ministers, David Lloyd George and Winston Churchill. After a spell as Lloyd George's parliamentary private secretary, he was a Government minister in the latter stages of the First World War. In later life the police's handling of a case in which he and factory worker Irene Savidge were acquitted of indecent behaviour aroused much political and public interest. A few years later he was convicted of an offence involving another woman.

Money was born in Genoa, Italy. His father was Anglo-Italian and his mother English. He was educated privately and, in 1903, largely anglicised his name, appending "Money" for what Lloyd George's biographer John Grigg has described as "eponymous reasons". He and his English wife Gwendoline had a daughter, Gwendoline Doris, born in 1896.

In London, Money established himself as a journalist, becoming especially noted for his use of statistical analysis. He has sometimes been referred to as a "New Liberal" economist. From 1898 to 1902 he was managing editor of Henry Sell's Commercial Intelligence, a journal devoted to the cause of free trade, which Money further championed in his books British Trade and the Zollverein Issue (July 1902) and Elements of the Fiscal Problem (1903). These were timely given the increasingly fervent political and public debate about Imperial Preference, a cause that led Joseph Chamberlain to resign from Arthur Balfour's Conservative government in 1903. Money argued that, although nobody was proposing a true "British Zollverein or Imperial Customs Union ... an imperial nation like ours cannot afford to benefit the colonies by giving a tariff preference to their products, for ... they cannot supply them in sufficient quantities to support our industries and people". His thinking appears to have had some influence on Winston Churchill, then a Conservative Member of Parliament (MP), who crossed to the Liberal Party in 1904 ostensibly because of his Free Trade principles; however, in later correspondence with Money, Churchill probably overstated the extent of his influence. Even so, Churchill told Money plainly in a letter in 1914 that he was "a master of efficient statistics and no one states a case with more originality or force".

In 1905 Money published the work for which he became most noted, Riches and Poverty. This analysis of the distribution of wealth in the United Kingdom, which he revised in 1912, proved influential and was widely quoted by socialists, Labour politicians and trade unionists. The future Labour Prime Minister, Clement Attlee, whose government (1945–51) established the modern welfare state, recalled that, while he was working at a boys' club at Haileybury, he had spent an evening studying Riches and Poverty. Among other things, Money claimed that 87% of private property was owned by 883,000 people (or 4.4 million if families and dependents were included), while the remaining 13% was shared between 38.6 million. These and other calculations were contested at the time as taking insufficient account of age and family structures, but were frequently cited as the best available figures of their kind. Money sought also to quantify Britain's middle class and its per capita wealth, calculating that 861,000 people in 1905 and 917,000 in 1912 owned property worth between £500 and £50,000, although, allowing for four dependents per property owner, the per capita figure was less than £1,000. In general his findings pointed to the modest size of most middle-class fortunes in Edwardian times, a picture broadly consistent with calculations made by Robert Giffen and Michael Mulhall in the 1880s (although Money took the view that business wealth was becoming increasingly concentrated in a few hands, whereas, towards the end of the 19th century, Giffen and others, such as Leone Levi, had concluded that such wealth was being spread more widely).

Around this time, Money sometimes shared Fabian platforms with such like-minded thinkers as Sidney Webb and H. G. Wells.

At the 1906 general election, in which the Liberal Party won a landslide victory, Money became Liberal MP for Paddington North. A future Conservative Lord Chancellor, F.E. Smith (later Lord Birkenhead), who also entered Parliament in 1906, poured sarcasm on the Free Trade aspects of Money's campaign (as he did on those of others), claiming that "with an infinitely just appreciation of his own controversial limitations, [Money] relied chiefly on the intermittent exhibition of horse sausages as a witty, graceful and truthful sally at the expense of the great German nation"

Money lost his seat at the January 1910 election, fought principally on the issue of the "People's Budget" delivered by Lloyd George as Chancellor of the Exchequer in 1909, but in December 1910 was elected for East Northamptonshire in the second general election of that year. He held that seat until 1918.

Lloyd George, who became Chancellor in 1908, valued Money's ability to develop innovative ideas; in 1911 he thanked him specifically for his "magnificent service" in relation to the new national insurance scheme and the following year contributed an introduction to his study of the Act and its purpose, published as Insurance Versus Poverty. In 1912 Money was active also in following up the sinking of the RMS Titanic, soliciting from the President of the Board of Trade (Sydney Buxton) an early breakdown of the number of passengers saved by class and gender. The figures showed, among other things, that, while 63% of first class passengers had survived, only 25% in third class had done so, including a mere 16 of 767 men in third class.