ignorantia juris non excusat

phrase

Ignorance of the law is not a valid excuse.

Meanings

phrase

alternative ignorantia juris neminem excusat · alternative ignorantia legis non excusat · alternative ignorantia legis neminem excusat

  1. Ignorance of the law is not a valid excuse.

    […] it is an offence against the duty of his place, and a forfeiture of his office; though I do believe Dr. Bury did not intend upon this to affront the bishop, but ignorantia juris non excusat; if the law be so, we cannot alter it.

    1908, “Term. Trin. 6 Will. & Mar. R. B.”, in The English Reports, volume XC: King’s Bench Division (XIX), Edinburgh: William Green & Sons, page 219
    2 more examples

    Dr Killen noted that while ignorantia juris non excusat (ignorance of the low is no excuse) may apply the advice showed that his father, the late Mr G. L. Killen, who was chairman and managing director of Marra at the time, was entitled to believe he was acting lawfully and properly.

    1979 December 29, Greg Bright, “Pressure off the Stock Exchange”, in The Sydney Morning Herald, number 44,318, page 28

    I pleaded no contest to a $15 parking ticket and Judge Pro Tem Noel Grefenson, probably eager to get lunch after a long morning, took mercy and discharged my fine with an admonishment of ignorantia juris non excusat. ¶ Actually, he didn’t scold me in Latin, but I got his drift nonetheless: “Ignorance of the law does not excuse” abiding by it.

    2004 October 29, Carol McAlice Currie, “Unposted laws make downtown seem unwelcoming”, in Statesman Journal, volume 152, number 214, Salem, OR, page 1C

Origin

  1. Latinignōrantia factī excūsat, ignōrantia jūris nōn excūsat“ignorance of fact excuses, ignorance of law does not excuse”
  2. Englishignorantia juris non excusat

Borrowed from Latin ignōrantia factī excūsat, ignōrantia jūris nōn excūsat (“ignorance of fact excuses, ignorance of law does not excuse”).

Full word history & related roots →
Cite this entry
APA

ignorantia juris non excusat. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/ignorantia%20juris%20non%20excusat

MLA

“ignorantia juris non excusat.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ignorantia%20juris%20non%20excusat. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “ignorantia juris non excusat,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/ignorantia%20juris%20non%20excusat.

Source: ignorantia juris non excusat on Wiktionary, CC BY-SA 4.0.