Clara Lucas Balfour (née Lucas; 21 December 1808 – 1878) was an English temperance campaigner, lecturer and author.
Clara Lucas was born in the New Forest, Hampshire, on 21 December 1808, the only child of John Lydell Lucas (c.1767–1818), a butcher and cattle dealer from Gosport, and his wife Sarah. Her parents appear to have separated when she was very young (it was later said that John had deceived Sarah into entering into a bigamous marriage), and Clara went to live with her father on the Isle of Wight. Following John's death in 1818, Clara was baptized, and taken by her mother to live in London. The two were not well off, and supported themselves by needlework.
In September 1824, not yet 16, Clara married James Balfour (1796–1884), of the Ways and Means Office in the House of Commons, her new home being in Chelsea.
In October 1837, James Balfour, an alcoholic, took a temperance pledge. Clara then herself took the pledge, a week or so later; this was at the Bible Christians' chapel, a meeting-place close by her house. Having adopted teetotalism, Clara then contacted Jabez Burns in 1840, and became a Baptist convert.
In the period 1837 to 1840, Balfour wrote Common Sense versus Socialism, a tract directed at a local Owenite group.Jane Carlyle called to thank her, and began a friendship. Importantly in practical terms, around this time Balfour also met the campaigner John Dunlop of Gairbraid. He gave her paid editorial work on the Temperance Journal in 1841.
In 1841 (after moving to Maida Hill), Balfour began a career as a temperance lecturer at the Greenwich Literary Institution. She continued the public advocacy of her principles for nearly thirty years. Her lectures were not confined to the temperance topic. She lectured on the influence of woman on society, and kindred subjects; and she held the post for some years of lecturer on belles lettres at a leading ladies' school.