Florence Petty (1 December 1870 – 18 November 1948) was a Scottish social worker, cookery writer and broadcaster. During the 1900s, in the socially deprived area of Somers Town, north London, Petty undertook social work for the St Pancras School for Mothers, commonly known as The Mothers' and Babies' Welcome. She ran cookery demonstrations for working-class women to get them in the habit of cooking inexpensive and nutritious food. Much of the instruction was done in the women's homes, to demonstrate how to use their own limited equipment and utensils. Because she taught the women firstly how to make suet puddings—plain, sweet and meat—her students nicknamed her "The Pudding Lady". In addition to her cookery lessons, she became a qualified sanitary inspector.

Petty wrote on cookery, publishing works aimed at those also involved in social work, including a cookery book—The Pudding Lady's Recipe Book, with Practical Hints (1917)—and pamphlet aimed at the public. Both the pamphlet and book contain practical information on how to make and use a haybox as a method of cooking, where heated food is placed in an insulated box to continue to cook, away from a heat source. Petty worked as a lecturer and cookery demonstrator for the National Food Reform Association, travelling round Britain to show cost-efficient and nutritious ways to cook despite the rising food prices and food shortages brought on by the First World War. She was a broadcaster on food and budgeting in the late 1920s and early 1930s, on the 2LO radio station for the BBC, as part of the "Household Talk" series of programmes aimed at housewives. From 1914 until the mid-1940s she toured Britain giving lecture-demonstrations on economical ingredients and cost-effective cooking methods.

Petty continued to work until her death in 1948 at the age of 77. Although no newspapers carried an obituary of her, historians consider her to be a pioneer of social work innovations, introducing a new approach to teaching domestic management. Her approach to teaching the use of nutritious but cheap food was a precursor to the method adopted by the Ministry of Food during the Second World War.

Florence Petty was born in Montrose, Forfarshire, on 1 December 1870. She was the fourth of seven children born to David James Petty, a clerk at a timber merchant's, and Jane Norris (née Levie). She lived in Montrose until her early 30s when she moved to Swanley, Kent, where she became involved in horticulture. She then moved in with her sister, a former nurse, who was living in Tottenham, north London.

Petty began working at the St Pancras School for Mothers (commonly known as The Mothers' and Babies' Welcome) which was active in the deprived area of Somers Town, north London. The philanthropist Charles Booth, in his 1889 poverty map, Life and Labour of the People in London, classed much of Somers Town—located between Euston and St Pancras railway stations—as the two worst categories: "Very poor, casual. Chronic want" and "Lowest class. Vicious, semi-criminal". Locals nicknamed the area "little hell". In the early twentieth century Somers Town had high levels of poverty; by the 1920s the area was "one of central London's most squalid slums", according to the architectural historian Roland Jeffery. In 1924 Basil Jellicoe, the vicar of the local St Mary's Church, wrote of the area's overcrowding and poverty; in 1930 one journalist described the housing as "vermin-ridden dens ... the worst hovels in London ... where mothers are afraid to put their children to bed for fear of rats and other vermin of all descriptions". The Mothers' and Babies' Welcome was run by the St Pancras Mothers' and Infants' Society, an organisation formed to combat high rates of infant mortality by educating mothers on nutrition and household management.

Among other activities, The Mothers' and Babies' Welcome provided cookery lessons for mothers, but realised that this was of limited success as many of the women lacked the basic equipment or utensils at home. Petty was employed to provide the cookery lessons in the women's own homes, demonstrating how they could use their existing equipment and utensils. Her approach was to give six lessons to show how people could cook cheap yet nutritious meals; she discussed the family's domestic and financial situation and wrote a series of case notes for those she visited.

Petty described herself as a "Lecturer and Demonstrator in Health Foods"; her students nicknamed her "The Pudding Lady" because, in an attempt to get the women in the habit of cooking regularly using familiar and inexpensive ingredients, for the first three months of her demonstrations they made suet puddings—plain, sweet and meat—until the women began to show pride in their ability to cook. Blake Perkins, Petty's biographer in the Oxford Dictionary of National Biography, considers that her notes on the families she was instructing are "matter-of-fact but also sympathetic rather than clinical".

In 1910 The Mothers' and Babies' Welcome published an account of Petty's work in The Pudding Lady: A New Departure in Social Work, examining the impact she had. The book was short—at 103 pages—and was aimed at "all who desire to raise the standard of life among our poorer fellow-citizens", according to the reviewer in the Charity Organisation Review. In the second edition, published in 1916, Charles Hecht, the secretary of the National Food Reform Association (NFRA)—the organisation that promoted higher standards in food production and whose aim was "to enlighten public opinion on matters of diet"—wrote that: