In the history of philosophy, 'Utilitarianism' was advocated by many philosophers. Epicurus is accepted as the first representative of utilitarianism. Furthermore, in Bentham's works, we can find out the first systematic theory of utilitarianism which is accepted by many philosophers like David Hume, John Locke. In this writing, the ideas of John Stuart Mill about utilitarianism, who is the greatest pragmatist following Bentham, will be analyzed. In this point, diferrent perspectives - different qualities which Mill contributed to the terms "happy" and "pain" and especially, different comments he contributed to the term "freedom - which Mill contributed to utilitarianism will be dealt with by referring to the similarities and differences of Mill and Bentham. Here, the comprehension of freedom will be explained with reference to the opinions of Mill on utilitarianism.