Progressivism is a left-leaning political philosophy and reform movement that seeks to advance the human condition through social reform. Adherents hold that progressivism has universal application and endeavor to spread this idea to human societies everywhere. Progressivism arose during the Age of Enlightenment out of the belief that civility in Europe was improving due to the application of new empirical knowledge.

In modern political discourse, progressivism is often associated with social liberalism, a left-leaning type of liberalism, and social democracy. Within economic progressivism, there is some ideological variety on the social liberal to social democrat continuum, as well as occasionally some variance on cultural issues; examples of this include some Christian democrat and conservative-leaning communitarian movements. While many ideologies can fall under the banner of progressivism, both the current and historical movement are characterized by a critique of unregulated capitalism, desiring a more active democratic government to take a role in safeguarding human rights, bringing about cultural development, and being a check-and-balance on corporate monopolies.

Immanuel Kant identified progress as being a movement away from barbarism toward civilization. 18th-century philosopher and political scientist Marquis de Condorcet predicted that political progress would involve the disappearance of slavery, the rise of literacy, the lessening of sex inequality, reform of prisons, which at the time were harsh, and the decline of poverty.

Modernity or modernisation was a key form of the idea of progress as promoted by classical liberals in the 19th and 20th centuries, who called for the rapid modernisation of the economy and society to remove the traditional hindrances to free markets and the free movements of people.

In the late 19th century, a political view rose in popularity in the Western world that progress was being stifled by vast economic inequality between the rich and the poor, minimally regulated laissez-faire capitalism with out-of-control monopolistic corporations, intense and often violent conflict between capitalists and workers, with a need for measures to address these problems. Progressivism has influenced various political movements. Social liberalism was influenced by British liberal philosopher John Stuart Mill's conception of people being "progressive beings." British Prime Minister Benjamin Disraeli developed progressive conservatism under one-nation Toryism.

In France, the space between social revolution and the socially conservative laissez-faire centre-right was filled with the emergence of radicalism which thought that social progress required anti-clericalism, humanism, and republicanism. Especially anti-clericalism was the dominant influence on the centre-left in many French- and Romance-speaking countries until the mid-20th century. In Imperial Germany, Chancellor Otto von Bismarck enacted various progressive social welfare measures out of paternalistic conservative motivations to distance workers from the socialist movement of the time and as humane ways to assist in maintaining the Industrial Revolution.

In 1891, the Roman Catholic Church encyclical Rerum novarum issued by Pope Leo XIII condemned the exploitation of labor and urged support for labor unions and government regulation of businesses in the interests of social justice while upholding the property right and criticising socialism. A progressive Protestant outlook called the Social Gospel emerged in North America that focused on challenging economic exploitation and poverty and, by the mid-1890s, was common in many Protestant theological seminaries in the United States.

Early 20th-century progressivism included support for American engagement in World War I and the creation of and participation in the League of Nations, compulsory sterilisation in Scandinavia, and eugenics in Great Britain, and the temperance movement. Progressives believed that progress was stifled by economic inequality, inadequately regulated monopolistic corporations, and conflict between workers and elites, arguing that corrective measures were needed.