The Humanitarian League was a British radical advocacy group formed by Henry S. Salt and others to promote the principle that it is wrong to inflict avoidable suffering on any sentient being.

[1] Howard Williams, the author of The Ethics of Diet (1883), a history of vegetarianism, proposed in the book the concept of a "humane society with a wider scope than any previously existing body".

Other founding members included Edward Maitland, Ernest Bell (Chairman),[3] Howard Williams, Kenneth Romanes and Alice Lewis (Treasurer).

Its aim was to enforce the principle that it is iniquitous to inflict avoidable suffering on any sentient being; their manifesto stated:[6]The Humanitarian League has been established on the basis of an intelligible and consistent principle of humaneness – that it is iniquitous to inflict suffering, directly or indirectly, on any sentient being, except when self-defence or absolute necessity can justly be pleaded.The League was a pioneering advocate for both animal and human rights, opposing corporal and capital punishment.

[5] The League also advanced human rights, playing a key role in the 1906 ban on flogging in the Royal Navy and campaigning to amend laws on imprisonment for debt and non-criminal offenses.