The most important thinkers and writers on utilitarian philosophy and ethics in 19th century Britain were Jeremy Bentham and John Stuart Mill. Their influence on political philosophy and ethics has been profound and, particularly in the case of Mill, continues to the present day.   

[Jeremy Bentham, detail of an oil painting by H.W. Pickersgill, 1829; in the National Portrait Gallery, London. Courtesy of the National Portrait Gallery, London. Encyclopedia Britannica Online.]