The Polish Peasant in Europe and America is a book by Florian Znaniecki and William I. Thomas, considered to be one of the classics of sociology.

The book is a study of Polish immigrants to the United States and their families, based on personal documents, and was published in five volumes in the years 1918 to 1920.

[10] He was also the originator of the concept of studying written materials for sociological insight, and initially intended this work to be a collection of translated and annotated primary documents.

Znaniecki convinced him to extend this project into a larger work, one with a more detailed analysis of the topic subject, its methodology and corresponding theory.

[11] Thomas and Znaniecki intended to explore the relation between individuals and society, focusing on groups such as families and neighborhoods, and community ties, which they believed were key to social change.

[21] Bulmer notes that "the subsequent use in sociological research of personal documents, such as life histories, letters, diaries, and other first-person material, may in large measure be traced back to the influence of The Polish Peasant.

[29][30] It was also one of the earliest works to study the topic of immigration to the United States, particularly with regards to trying to understand both the European and the American social context.

[29] A year later, Herbert Blumer headed a commission which produced an extensive, approximate 200-pages analysis of the book, and became the first tome in a series of Critiques of Research in the Social Science.