The Subjection of Women is an essay by English philosopher, political economist and civil servant John Stuart Mill published in 1869, with ideas he developed jointly with his wife Harriet Taylor Mill. Mill submitted the finished manuscript of their collaborative work On Liberty (1859) soon after her untimely death in late 1858, and then continued work on The Subjection of Women until its completion in 1861. At the time of its publication, the essay's argument for equality between the sexes was an affront to European conventional norms regarding the status of men and women.

In his autobiography, Mill describes his indebtedness to his wife, and his daughter Helen Taylor for the creation of The Subjection of Women:

As ultimately published it was enriched with some important ideas of my daughter’s and some passages of her writing. But all that is most striking and profound in what was written by me belongs to my wife, coming from the fund of thought that had been made common to us both by our innumerable conversations and discussions on a topic that filled so large a place in our minds.

While scholars generally agree that John Stuart Mill was the sole author, it is also noted that some of the arguments are similar to Harriet Taylor Mill's essay The Enfranchisement of Women, which was published in 1851.

John Stuart Mill (20 May 1806 – 7 May 1873) was an English philosopher, political economist, Member of Parliament (MP) and civil servant. One of the most influential thinkers in the history of classical liberalism, he contributed widely to social theory, political theory, and political economy. Dubbed "the most influential English-speaking philosopher of the nineteenth century", he conceived of liberty as justifying the freedom of the individual in opposition to unlimited state and social control.