Nihil novi nisi commune consensu ("Nothing new without the common consent") is the original Latin title of a 1505 act or constitution adopted by the Polish Sejm (parliament), meeting in the royal castle at Radom.
The Latin expression, "nihil novi" ("nothing new"), had previously appeared in the Vulgate Bible phrase, "nihil novi sub sole" ("there is nothing new under the sun"), in Ecclesiastes 1:9.
"Nihil novi" in this political sense, is interpreted in the vernacular as "Nothing about us without us" (in Polish, "Nic o nas bez nas").
Nihil novi effectively established "nobles' democracy" in what came to be known as the Polish "Commonwealth [or Republic] of the Nobility". It was a major component of the evolution and eventual dominant position of the Polish parliament (Sejm).
The act of Nihil novi was passed in 1505 during a Sejm session in Radom (sejm of Radom (1505)) that lasted from 30 March to 31 May and was held at the royal castle in Radom. It was signed by King Alexander Jagiellon on 31 March and passed by Sejm on 30 May.
The Sejm'''s 1505 Act of Nihil novi nisi commune consensu marked an important victory for Poland's nobility over her kings. It forbade the king to issue laws without the consent of the nobility, represented by the Senat and Chamber of Deputies, except for laws governing royal cities, crown lands (królewszczyzny), mines, fiefdoms, royal peasants, and Jews.
Nihil novi invalidated the Privilege of Mielnik, which had strengthened only the magnates, and it thus tipped the balance of power in favor of the Chamber of Deputies (the formally lower chamber of the Parliament), where the ordinary nobility held sway. Nihil novi is often regarded as initiating the period in Polish history known as "Nobles' Democracy," which was but a limited democracy as only male nobility (szlachta) were able to participate (the nobility constituting some ten percent of the Republic's population, still a higher eligible percentage than in much of Europe).