Liberalism in Brazil refers to a set of political ideas and parties that, since the nineteenth century, have advocated constitutional government, representative institutions, individual rights, and—at varying times—decentralisation and market-oriented economic policy. In the imperial era, self-described liberals (known as luzias) opposed centralising conservatives (saquaremas) within a constitutional monarchy; in the twentieth and twenty-first centuries, "liberal" labels have been adopted by a variety of organisations spanning centre to right, reflecting Brazil's fragmented party system and shifting ideological coalitions.

Since the 1985 return to civilian rule, parties that academics classify as liberal or liberal-conservative have included the Liberal Front Party (later Democrats), the Brazilian Democratic Movement, the Brazilian Social Democracy Party, and more recently groups such as the New Party (NOVO); usage remains contested, with some "liberal" brands aligning with conservative or populist currents.

In nineteenth-century Brazil the term liberal denoted adherents of representative constitutionalism who favoured greater provincial autonomy and limits on the Moderating Power of the emperor. Their rivals, the Conservatives, defended a stronger central state; the two labels—luzias and saquaremas—became shorthand for the main parliamentary blocs of the Second Reign (1840–1889). In the twentieth century, liberalismo often signified economic liberalisation—privatisation, trade opening, and fiscal adjustment—while civil-liberties and social-liberal currents coexisted within different parties and movements. Political scientists caution that party labels in Brazil frequently mask heterogeneous coalitions, so "liberal" parties may range from centrist to conservative-liberal, or even align with right-wing populism.

Liberal language entered Brazilian politics during the Independence conjuncture, when merchants, professionals, and provincial elites in Rio de Janeiro and other ports linked market interests to projects for representative government and local autonomy. The 1824 Constitution proclaimed individual guarantees and a representative legislature while preserving slavery and creating the emperor's "Moderating Power" (Poder Moderador), an arrangement scholars describe as a paradoxical blend of liberal rights with hierarchical social order. Imperial "conservative liberalism" fused constitutional monarchy with a slave-based economy and, after the upheavals of the 1820s, privileged order and executive strength over mass participation.

After 1831, a self-styled Liberal Party (the luzias) crystallised as one pole of parliamentary life against the Conservatives (the saquaremas). Liberals generally favoured decentralisation—reflected in the Additional Act of 1834—while recurrent schisms produced offshoots such as the Progressive League in the 1860s and a short-lived "New Liberal" current around Joaquim Nabuco in 1869. Mid-century elites portrayed politics as "action, reaction, and transaction," using conciliation to contain radical and republican currents; critics likened the regime's party rotation to "Penelope's plot," forever doing and undoing under monarchical tutelage.

Contemporary British observers contrasted instability in Spanish American republics with Brazil's "flourishing constitutional, hereditary monarchy," a trope that legitimated strong crown prerogatives within a nominally liberal order. Imperial liberalism's social limits were visible in contemporary defenses of slavery. Reporting a conversation with deputy Bernardo Pereira de Vasconcelos, the British traveler Robert Walsh recorded a civilizational justification for enslavement shared among conservative liberals. From the 1870s, a "second generation" of liberals—including Nabuco—reframed abolition as essential to a liberal polity, linking emancipation to civic life and constitutionalism; debates over gradualist "liberal solutions" to slavery culminated in the 1888 abolition law.

A constitutional flashpoint came in 1868, when José Thomaz Nabuco de Araújo's celebrated critique of the emperor's "neutral power" (the so-called "false syllogism") charged that legal prerogatives were eroding popular legitimacy; the fall of the monarchy in 1889 scattered liberals across emergent republican factions.

In the First Republic, liberal institutions coexisted uneasily with regional oligarchies and weak civic integration. Episodes such as the Canudos War (1896–97) and the 1904 Vaccine Revolt fed a diagnosis—one prominent in early twentieth-century debate—that representative forms had shallow social roots and needed active state-building to take hold.