Selina, Countess of Huntingdon (August 24, 1707 - June 17, 1791) was an English religious leader who played a prominent part in the Methodist movement in England and Wales.

She was born as Selina Shirley, the second daughter of Washington Shirley, 2nd Earl Ferrers , at Staunton Harold, a mansion near Ashby-de-la-Zouch in Leicestershire. She married Theophilus Hastings, 9th Earl of Huntingdon , on June 3, 1728.

In 1739 she joined the first Methodist society in Fetter Lane, London. After the death of her husband in (1746 or 1747?), she threw in her lot with Wesley and George Whitefield in the work of the great revival. Whitefield became her personal chaplain, and, with his assistance, she founded the "Countess of Huntingdon's Connexion", a radical Calvinistic movement within the Methodist church. Isaac Watts, Philip Doddridge, and Augustus Montague Toplady were among her friends. In 1748 she gave Whitefield a scarf as her chaplain, and in that capacity he frequently preached in her London house in Park Street to audiences that included Chesterfield, Walpole and Bolingbroke.

She was responsible for the founding of sixty-four chapels, for example at Brighton (1761), London and Bath (1765), Tunbridge Wells (1769), and several in Wales. She appointed ministers to officiate in them, under the impression that as a peeress she had a right to employ as many chaplains as she pleased. In her chapel at Bath there was a curtained recess dubbed Nicodemus' corner where some of the bishops sat incognito to hear him. She also founded the ministers' training college at Trefeca near Brecon, which later moved to Hertfordshire.

It is said that she expended 100,000 pounds in the cause of religion. In 1768 she converted the old mansion of Trefeca, near Talgarth, in South Wales, into a theological seminary for young ministers for the connexion. Up to 1779 Lady Huntingdon and her chaplains were members of the Church of England, but in that year the prohibition of her chaplains by the consistorial court from preaching in the Pantheon, a large building in London rented for the purpose by the countess, compelled her, in order to evade the injunction, to take shelter under the Toleration Act . This step, which placed her legally among dissenters, had the effect of severing from the connexion several eminent and useful members, among them William Romaine (1714-1795) and Henry Venn (1725-1797).

Till her death in London, Lady Huntingdon continued to exercise an active, and even autocratic, superintendence over her chapels and chaplains. She successfully petitioned George III about the gaiety of Archbishop Cornwallis' establishment, and made a vigorous protest against the anti-Calvinistic minutes of the Wesleyan Conference of 1770, and against relaxing the terms of subscription of 1772. Her sixty-four chapels and the college were bequeathed to four trustees. In 1792 the college was removed to Cheshunt, Hertfordshire, where it remained till 1905, when it was transferred to Cambridge. The college is noted for the number of men it has sent into the foreign mission field.

A slave owner herself, she promoted the writings of African slaves like authors Ukawsaw Gronniosaw, Phyllis Wheatley and Olaudah Equiano. Following her death, her movement merged with the Congregationalist Church.