Throughout twentieth-century Ukraine, letters were lifelines. Under two of history's most repressive regimes - the Soviet Union and Nazi Germany - Ukrainians wrote to sustain family ties, affirm identity, and resist erasure, even as every word passed through the machinery of surveillance and censorship. Drawing on newly uncovered archival materials, including documents from the Ukrainian Archives of the former KGB, this groundbreaking work is the first comprehensive study of censorship and epistolary culture in Ukraine under totalitarian rule. The volume reveals how correspondence functioned as an emotional artifact, a political instrument, and a historical document, showing how the act of writing could be both deeply personal and profoundly political. Postal Censorship, Surveillance, Resistance adopts an interdisciplinary framework to examine how systems of control shaped the practices of letter-writers - from Ostarbeiters and Gulag prisoners to diaspora families, Jews, former communists, émigrés, and Mennonites - who devised strategies of resilience through metaphor, folklore, and coded language. The book positions Ukraine as a crucial site of both postal repression and subversive ingenuity, while highlighting the persistence of human creativity in the face of silencing. Ten key instructional documents of the Soviet secret services, spanning 1940 to 1990, are presented in an appendix, giving readers direct insight into the rules and mechanisms of surveillance. Bridging history, anthropology, literary studies, and memory studies, and grounded in rich primary sources, Postal Censorship, Surveillance, Resistance is essential reading for specialists in Ukrainian and Slavic studies and scholars interested in censorship, propaganda, and totalitarianism.