Emma Jane Catherine Cobden (28 April 1851 – 7 July 1947) was a British Liberal politician who was active in many radical causes. A daughter of the Victorian reformer and statesman Richard Cobden, she was an early proponent of women's rights, and was one of two women elected to the inaugural London County Council in 1889. Her election was controversial; legal challenges to her eligibility hampered and eventually prevented her from serving as a councillor.

From her youth Jane Cobden, together with her sisters, sought to protect and develop the legacy of her father. She remained committed throughout her life to the "Cobdenite" issues of land reform, peace, and social justice, and was a consistent advocate for Irish independence from Britain and for women's suffrage. Although she was sympathetic and supportive of those, including her sister Anne Cobden-Sanderson, who chose to campaign using militant, illegal methods, she kept her own activities within the law. She stayed in the Liberal Party, despite her profound disagreement with its stance on the suffrage issue.

After her marriage to the publisher Thomas Fisher Unwin in 1892, Jane Cobden extended her range of interests into the international field, in particular advancing the rights of indigenous populations within colonial territories. As a convinced anti-imperialist she opposed the Boer War of 1899–1902, and after the establishment of the Union of South Africa in 1910 she attacked its introduction of segregationist policies. In the years prior to World War I she opposed Joseph Chamberlain's tariff reform crusade on the grounds of her father's free trade principles, and was prominent in the Liberal Party's revival of the land reform issue. In the 1920s she largely retired from public life, and in 1928 presented the old Cobden family residence, Dunford House, to the Cobden Memorial Association as a conference and education centre dedicated to the issues and causes that had defined Cobdenism.

Jane Cobden was born on 28 April 1851 in Westbourne Terrace, London. She was the third daughter and fourth child of Richard Cobden, who at the time of her birth was a member of parliament for the West Riding. With John Bright he had co-founded the Anti-Corn Law League which in the 1840s had spearheaded the successful campaign for the abolition of the Corn Laws. Jane's mother was Catherine Anne, née Williams, the daughter of a timber merchant from Machynlleth in Wales; the older Cobden children were Richard ("Dick"), born 1841; Kate, born 1844; and Ellen, born 1848. Two further daughters followed Jane: Anne, born 1853, and Lucy, born 1861.

In the 1830s, Richard had handed control of his prosperous calico-printing business to his brothers, so that he could concentrate on public service. By 1849, the business was failing and Richard was close to financial ruin. He was saved from bankruptcy by a public subscription which not only settled his debts but also enabled him to acquire the farmhouse in which he had been born in 1804, at Dunford, near Heyshott in Sussex. He rebuilt the property as a large villa, Dunford House, which became Jane Cobden's childhood home from the beginning of 1854. In April 1856 Dick, who was at school at Weinheim in Germany, died there after a short illness. The news was a devastating shock to the family, and caused Richard's temporary withdrawal from public life. This hiatus was prolonged when, in 1857, he lost his parliamentary seat. He returned to the House of Commons in May 1859, as Liberal MP for Rochdale.

Because of his many absences from home, on parliamentary and other business, Richard Cobden was a somewhat remote figure to his daughters, although his letters indicate that he felt warmly towards them and that he wished to direct their political education. In later years they would all acknowledge his influence over their ideas. Both parents impressed on the girls their responsibilities for the poor in the local community; Jane Cobden's 1864 diary records visits to homes and workhouses. She and her younger sister Anne, at the ages of 12 and 10 respectively, taught classes in the local village school. The girls were encouraged by their father to contribute what money they possessed to relieve local poverty: "Do not keep the money ... as you have now made up your minds to give it to poor sufferers, let your own neighbours have it. Your Mama will tell you how to dispose of it, and tell me all about it".

Richard Cobden died after a severe bronchial attack on 2 April 1865, a few weeks before Jane's 14th birthday. There followed a time of domestic uncertainty and financial worry, eventually resolved by a pension from the government of £1,500 a year, and the establishment of a "Cobden Tribute Fund" by his friends and followers. After their father's death Jane and Anne attended Warrington Lodge school in Maida Hill but, following a disagreement the nature of which is unclear, both were removed from the school—"thrown on my hands", their mother complained. In this difficult time, Catherine did not withdraw into seclusion; in 1866 she supervised the re-publication of her husband's Political Writings, and in the same year became one of the 1,499 signatories to the "Ladies Petition", an event that the historian Sophia Van Wingerden marks as the beginning of the organised women's suffrage movement.

"No more aimless wanderings abroad for me, I shall enter into the Women's Suffrage Campaign and so have a real interest in life".