Petras Vileišis (Polish: Piotr Wilejszys; 25 January 1851 – 12 August 1926) was a prominent Lithuanian engineer specializing in the construction of railroad bridges.

In 1899, he returned to Lithuania and settled in Vilnius where he built Vileišis Palace and established the first Lithuanian-language daily newspaper Vilniaus žinios as well as a Lithuanian printing press, bookstore, and ironwork factory which later became Vilija.

When the censorship office caught on the error, Vileišis published at least 55 books in East Prussia and United States that were smuggled into Lithuania.

He also continuously petitioned and lobbied various Russian officials, including Minister of Finance Sergei Witte and Governor-General of Vilnius Pyotr Sviatopolk-Mirsky, to get the press ban lifted.

His brother Jonas even claimed that Vileišis spent considerable sums in bribing Russian officials to get the ban lifted in 1904.

[33] Vileišis and the group established the Lithuanian-language newsletter Kalvis melagis (Smith the Liar) in violation of the Lithuanian press ban.

In 1875, Vileišis wrote a 47-page popular science work on earth and weather which was approved by the state censor and 2,000 copies were published next year.

[38] He prepared many other educational and didactic booklets, including a prayer book, for the common village folk but the state censors rejected all of them due to the Lithuanian press ban.

According to studies of Vaclovas Biržiška, in total Vileišis published 59 books: four in Saint Petersburg, five in United States, and 50 in East Prussia.

[51] In addition, Vileišis supported Lithuanian periodicals, including Aušra, Varpas, Garsas, Nemuno sargas, both financially and by contributing articles for publication.

[55] Vileišis also influenced Pyotr Sviatopolk-Mirsky, the new Governor-General of Vilnius, who wrote to Vyacheslav von Plehve, Minister of the Interior, arguing that the press ban should be lifted.

[63] Its larger projects in Vilnius included the metal framework for the Halė Market [lt], parts for the Žvėrynas Bridge, and decorative elements for the Vileišis Palace.

Lithuanians petitioned bishop Stefan Aleksander Zwierowicz and managed to obtain Church of Saint Nicholas for their purposes in December 1901.

[68] During the Russian Revolution of 1905, he was a vocal advocate for education reforms and co-signed petitions on introducing Lithuanian language, literature, history to school curriculums and on reestablishing Vilnius University.

[76] Due to Vileišis conservative political stance, the newspaper did not cover the Russian Revolution of 1905 and did not develop a more distinctive editorial voice.

[86] None of Vileišis activities in Vilnius (ironwork factory, daily newspaper, printing press, bookstore) were profitable and by 1908 he had exhausted his savings and incurred debts.

[93] At the time, Vilnius (and his palatial home) was part of the Second Polish Republic and he moved to a cheap hotel in Kaunas, the temporary capital of Lithuania.

[90] Soon after his return to Lithuania, Vileišis started writing and publishing articles criticizing Żeligowski's Mutiny and attempts by the League of Nations to mediate the dispute over Vilnius Region.

[98] Vileišis translated International Law of Civilised Nations by Friedrich Martens and hoped to publish it with the help of the University of Lithuania.

[109] The funeral was attended by President Kazys Grinius, Prime Minister Mykolas Sleževičius, Speaker of the Seimas Jonas Staugaitis, and other dignitaries.

[109] After a brief stop at the War Museum and a Catholic mass by Archbishop Juozas Skriveckas, Vileišis was temporarily buried in a crypt of Kaunas Cathedral.

Already in 1991, his 140th birth anniversary, the Martynas Mažvydas National Library of Lithuania and the community of Pasvalys organized exhibitions, readings, and memorials.

[122] Objects named after Vileišis during the interwar period were again renamed in his honor – the school in Pasvalys in 1989, the square and street in Kaunas in 1989 and 1991, the bridge across Neris in 2008; the bust in the garden of the War Museum was reconstructed in 1989.

In 1883, his first publication in East Prussia, was agricultural advice written by Ignacy Łyskowski [pl] and translated from Polish by Vincas Pietaris.

[131] Vileišis also published booklets on cattle (1884), on gardens, hops, and bees (1885),[132] cows and milk (1892), horses and their illnesses (1893), potatoes (1900), oats (1902), etc.

[133] In 1902–1903, he published three textbook-type booklets about selected crafts (including lathing, metal working, brush, wheel, and rope making, tanning of leather and furs).

[137] Vileišis published several books about or by famous businessmen, including the pioneer of rail transport George Stephenson, American showman P. T. Barnum, banker and archaeologist John Lubbock, 1st Baron Avebury.

[134] While Vileišis promoted wealth accumulation, he emphasized ethics – good moral character, strong will and determination, hard work and frugality.

[144] Another memoir published by Pranas Stanaitis in 1929 claimed that Vileišis spoke French to his wife at home, but used Lithuanian to speak to their children.

[146] The couple had six children: Jonas (1886–1946) who became an attorney, Vytautas [lt] (1887–1937) who was Minister of Transport in 1929–1934, Elena Vileišytė-Jaloveckienė (1889–1953), Marija Vileišytė-Baženskienė (1891–1944) who published two collections of Polish poetry in 1920s, Petras (1892–1904) who died suddenly of brain inflammation, and Kazimiera Birutė Vileišytė-Stulginskienė (1894–1971).