De Profundis (Latin: "from the depths") is a letter written by Oscar Wilde during his imprisonment in Reading Gaol, to "Bosie" (Lord Alfred Douglas).

In its first half Wilde recounts their previous relationship and extravagant lifestyle which eventually led to Wilde's conviction and imprisonment for gross indecency. He indicts both Lord Alfred's vanity and his own weakness in acceding to those wishes. In the second half, Wilde charts his spiritual development in prison and identification with Jesus Christ, whom he characterises as a romantic, individualist artist. The letter began "Dear Bosie" and ended "Your Affectionate Friend".

Wilde wrote the letter between January and March 1897, close to the end of his imprisonment. Contact had lapsed between Douglas and Wilde and the latter had suffered from his close supervision, physical labour, and emotional isolation. Nelson, the new prison governor, thought that writing might be more cathartic than prison labour. He was not allowed to send the long letter which he was allowed to write "for medicinal purposes"; each page was taken away when completed, and only at the end could he read it over and make revisions. Nelson gave the long letter to him on his release on 18 May 1897.

Wilde entrusted the manuscript to the journalist Robert Ross (another former lover, loyal friend, and rival to "Bosie"). Ross published the letter in 1905, five years after Wilde's death, giving it the title "De Profundis" from Psalm 130. It was an incomplete version, excised of its autobiographical elements and references to the Queensberry family; various editions gave more text until in 1962 the complete and correct version appeared in a volume of Wilde's letters.

Wilde's work was written as a prose letter on twenty sheets of prison paper. It contains no formal divisions (save paragraphs) and is addressed and signed off as a letter. Scholars have distinguished a noticeable change in style, tone and content in the latter half of the letter, when Wilde addresses his spiritual journey in prison. In the first part, Wilde examines the time he and Lord Alfred had spent together, from 1892 until Wilde's trials in the spring of 1895. He examines Lord Alfred's behaviour and its detrimental effect on Wilde's work, and recounts Lord Alfred's constant demands on his attention and hospitality. Poignancy builds throughout this section as Wilde details the expenses of their sumptuous dinners and hotel-stays, many costing over £1,000; it culminates in an account of Douglas's rage in Brighton whilst Wilde was ill. Though he was a constant presence at Wilde's side, their relationship was intellectually sterile. Throughout Wilde's self-accusation is that he acceded to these demands instead of placing himself within quiet, intellectual company dedicated to the contemplation of beauty and ideas, but instead succumbed to an "imperfect world of coarse uncompleted passions, of appetite without distinction, desire without limit, and formless greed".[16] This passage concludes with Wilde offering his forgiveness to Douglas. He repudiates him for what Wilde finally sees as his arrogance and vanity; he had not forgotten Douglas's remark, when he was ill, "When you are not on your pedestal you are not interesting."