In 1869 Beesly married Emily, youngest daughter of Sir Charles John Crompton, justice of the queen's bench, and his wife, Caroline. The Beeslys lived in University Hall until 1882, when they moved to Finsbury Park. Mrs Beesly was not a positivist—as were her brothers Albert and Henry Crompton—but she shared some of her husband's political and historical interests. He unsuccessfully stood for parliament as a Liberal at Westminster in November 1885 and at Marylebone in July 1886. Emily Beesly became president of the women's liberal association of Paddington after their move to Warrington Crescent in 1886. Both advocated Irish home rule, he in hard-hitting articles, she in new lyrics for "The Wearing of the Green". In 1878 he published "Catiline, Clodius, and Tiberius", and she brought out her "Stories from the History of Rome", written for their four sons. She died in 1889, aged forty-nine.