Paul Werth joined the University of Nevada, Las Vegas in 1997, after receiving his PhD at the University of Michigan in 1996, and is now Professor in the Department of History. He has been a fellow at the Slavic Research Center at the University of Hokkaido (Japan); at the National Humanities Center in North Carolina; and at the Center for Advanced Study at Ludwig-Maximilians University in Munich (Germany). From 2010 to 2015 he was one of the three editors of the journal Kritika: Explorations in Russian and Eurasian History. In 2013-14 he was chair of UNLV's Faculty Senate, after that serving as chair of UNLV's Promotion & Tenure Committee and then chair of its Department of History (2015-17) and Undergraduate Coordinator in that department (2019-22). In 2022 he was named a Fellow of the John Simon Guggenheim Memorial Foundation, and for the Spring Semester of 2023 he is a Gerhard Casper Fellow at the American Academy in Berlin. He has furthermore been selected as a fellow for the Swedish Collegium of Advanced Studies in Uppsala (2024). 

His research focused initially on religious freedom in the Russian Empire and the role of religious institutions and personnel in tsarist imperial governance. He has published articles in Social History, Slavic Review, Nationalities Papers, Kritika, Comparative Studies in Society and History, Russian Review, Ab Imperio, Cahiers du Monde russe, Journal of Modern History. His first book, At the Margins of Orthodoxy, was published with Cornell in 2002, and a book of his essays in Russian translation appeared in 2012 as Православие, инославие, иноверие (NLO). In 2014 he completed The Tsar's Foreign Faiths: Toleration and the Fate of Religious Freedom in Imperial Russia (Oxford). Among his current projects on this area of research is Russia’s Other Eastern Church, an exploration of the place of the Armenian confession in tsarist Russia’s religious and geopolitical landscape.

His more recent scholarship has moved in new directions. In 2021 he published 1837: Russia's Quiet Revolution (Oxford), a book intended to reveal the dynamism and consequence of a neglected but critical moment in Russia’s history. He has since turned to questions of borders, territory, and sovereignty, and is currently writing A Territorial History of Russia, which covers seven centuries of Muscovite, imperial, Soviet, and post-Soviet Russian space (planned for release with Bloomsbury Publishers in 2025); and Russia’s Enclosure: A History of the Longest Border (contracted with Oxford University Press), which explores Russia's boundaries from Norway to North America, and from the early modern period to the present.