Wills was the second son of William Wills, JP, of Edgbaston, Birmingham, and of his wife Sarah Wills, a daughter of Jeremiah Ridout. He was educated at King Edward's School, Birmingham and at University College London, where he held exhibitions and scholarships in Mathematics, Classics and Law, graduating BA in 1849 and LLB in 1851.
Wills was called to the bar by the Middle Temple in 1851 and was appointed Queen's Counsel in 1872. He was first Recorder of Sheffield, 1881–84; a Judge of the Queen's and King's Bench Division of the High Court of Justice, 1884–1905, President of the Railway and Canal Commission, 1888–1893, and Treasurer of the Middle Temple, 1892–1893.
During his career as a judge, his most notable achievement was presiding over the trial in which Oscar Wilde was convicted for "committing acts of gross indecency with other male persons". Willis sentenced Wilde to two years' hard labour. The judge described the sentence, the maximum allowed, as "totally inadequate for a case such as this," and that the case was "the worst case I have ever tried". Wilde's response "And I? May I say nothing, my Lord?" was drowned out in cries of "Shame" in the courtroom.
With his father William Wills, he co-authored An essay on the principles of circumstantial evidence : illustrated by numerous cases (1905), still a standard text often cited.[who?]
The ascent of the Wetterhorn above Grindelwald in the Bernes Alps by Wills and his party in 1854, which Wills mistakenly believed was the first (actually summited a decade earlier by local guides Melchior Bannholzer and Hans Jaun on 31 August 1844) is considered the beginning of the so-called golden age of alpinism. His account of the expedition helped make climbing mountains as sport fashionable.
He was the third President of the Alpine Club from 1863 to 1865.
- Wanderings among the High Alps (1856)
- The Eagle's Nest in the Valley of Sixt (1860)
- Wills on Circumstantial Evidence (ed.)
- Rendu's Théorie des Glaciers de la Savioe (translation)
In 1854 Wills married Lucy, daughter of George Martineau. She died in 1860, and in 1861 he married Bertha, daughter of Thomas Lombe Taylor, of Starston, Norfolk. His second wife died in 1906. He had three sons and two daughters.
- "brief review of The Eagle's Nest in the Valley of Sixt". Christian Examiner and Theological Review: 461. November 1860.
-  Vanity Fair, The Honourable Sir Alfred Wills, 9 W. Res. L. Rev. 1 reprinted (1957) in the Case Western Reserve Journal of International Law (accessed 20 December 2020)