The following events related to sociology occurred in the 1900s (decade).

1900

• Sigmund Freud's The Interpretation of Dreams is published.
• Georg Simmel's The Philosophy of Money is published.

1901

• Benjamin Seebohm Rowntree's Poverty, A Study of Town Life is published.

1902

• Charles Horton Cooley's Human Nature and the Social Order is published.
• Vladimir Ilyich Ulyanov Lenin's What is to be Done? is published.
• Werner Sombart's Der moderne Kapitalismus is published
• Lester Frank Ward's Dynamic Sociology is published.
• Beatrice Webb's and Sidney Webb's Problems of Modern Industry is published.

1903

• Victor Branford's On the origin and use of the word Sociology and on the relation of sociological to other studies and to practical problems is published.
• Charles Booth's Life and Labour of the People of London is published.
• W. E. B. Du Bois' The Souls of Black Folk is published.
• Émile Durkheim's and Marcel Mauss' Primitive Classification is published.
• Charlotte Perkins Gilman's The Home: Its Work and Influences is published.
• Georg Simmel's The Metropolis and Mental Life is published.
• Lester Frank Ward's Pure Sociology is published.

1904

• Leonard Trelawny Hobhouse's Democracy and Reaction is published.
• Thorstein Bunde Veblen's The Theory of Business Enterprise is published.
• British Sociological Society is founded, James Bryce is elected first president.

1905

• Jane Addams's An International Patriotism is published.
• Georg Simmel's Philosophy of Fashion is published.
• Max Weber's The Protestant Ethic and the Spirit of Capitalism is published.
• The American Sociological Society is founded; this is later renamed the American Sociological Association.
• The School of Sociology set up by the Charity Organisation Society for the training of Social Workers.

1906

• Werner Sombart's Why is there no Socialism in the United States? is published.
• William Graham Sumner's Folkways is published.
• Lester Frank Ward's Applied Sociology is published.

1907

• Henri Bergson's Creative Evolution is published.
• Albion Small's General Sociology is published.
• Albion Small's Adam Smith and Modern Sociology is published.
• H.G. Wells' The So-Called Science of Society is published.
• Chair of Sociology at the London School of Economics founded, the first in the United Kingdom, and is taken by Leonard Trelawny Hobhouse.

1908

• Friedrich Nietzsche's Ecce Homo is published.
• Georg Simmel's Sociology: Investigations on the Forms of Sociation (including "The Dyad" and "The Stranger") is published.
• Georges Sorel's Reflections on Violence is published.
• Georges Sorel's The Illusions of Progress is published.

1909

• Charles Cooley's Social Organization is published.
• Mary Coolidge's Chinese Immigrants is published.
• Charles Arnold van Gennep's Rites of Passage is published.
• Maurice Halbwach's Thèse de Droit is published.
• Leonard Trelawny Hobhouse's The Origin and Development of Moral Ideas is published.
• Karl Kautsky's Road to Power is published.
• W. I. Thomas' Source Book of Social Origins is published.
• The German Society for Sociology Is Founded by Max Weber, Georg Simmel and Ferdinand Tönnies among others, Tonnies serves as first president.