Alt or ALT may refer to:
Alternative rock (also called alternative music, alt-rock or simply alternative) is a genre of rock music that emerged from the independent music underground of the 1980s and became widely popular in the 1990s and 2000s.
Alternative medicine or fringe medicine are practices claimed to have the healing effects of medicine but which are disproven, unproven, or impossible to prove, or are excessively harmful in relation to their effect; and where the scientific consensus is that the therapy does not, or can not, work because the known laws of nature are violated by its basic claims; or where it is considered so much worse than conventional treatment that it would be unethical to offer as treatment.
The alternative minimum tax (AMT) is a supplemental income tax imposed by the United States federal government required in addition to baseline income tax for certain individuals, corporations, estates, and trusts that have exemptions or special circumstances allowing for lower payments of standard income tax.
Alternating current (AC), is an electric current which periodically reverses direction, whereas direct current (DC, also dc) flows only in one direction.
Altruism or selflessness is the principle or practice of concern for the welfare of others. It is a traditional virtue in many cultures and a core aspect of various religious traditions and secular worldviews, though the concept of "others" toward whom concern should be directed can vary among cultures and religions.
Alternate history or alternative history (British English), sometimes abbreviated as AH, is a genre of fiction consisting of stories in which one or more historical events occur differently.
Alternative for Germany (German: Alternative für Deutschland, AfD) is a right-wing populist and Eurosceptic political party in Germany.
Alton Towers Resort, commonly referred to as Alton Towers, is a theme park, water park, and hotel complex in Staffordshire, England.
The alt-right, or alternative right, is a loose group of people with far-right ideologies who reject mainstream conservatism in the United States.