New Age is a range of spiritual or religious practices and beliefs which rapidly grew in Western society during the early 1970s. Its highly eclectic and unsystematic structure makes a precise definition difficult. Although many scholars consider it a religious movement, its adherents typically see it as spiritual or as unifying Mind-Body-Spirit, and rarely use the term New Age themselves. Scholars often call it the New Age movement, although others contest this term and suggest it is better seen as a milieu or zeitgeist.

As a form of Western esotericism, the New Age drew heavily upon esoteric traditions such as the occultism of the eighteenth and nineteenth centuries, including the work of Emanuel Swedenborg and Franz Mesmer, as well as Spiritualism, New Thought, and Theosophy. More immediately, it arose from mid-twentieth century influences such as the UFO religions of the 1950s, the counterculture of the 1960s, and the Human Potential Movement. Its exact origins remain contested, but it became a major movement in the 1970s, at which time it was centered largely in the United Kingdom. It expanded widely in the 1980s and 1990s, in particular in the United States. By the start of the 21st century, the term New Age was increasingly rejected within this milieu, with some scholars arguing that the New Age phenomenon had ended.

Despite its eclectic nature, the New Age has several main currents. Theologically, the New Age typically accepts a holistic form of divinity that pervades the universe, including human beings themselves, leading to a strong emphasis on the spiritual authority of the self. This is accompanied by a common belief in a variety of semi-divine non-human entities, such as angels and masters, with whom humans can communicate, particularly by channeling through a human intermediary. Typically viewing history as divided into spiritual ages, a common New Age belief is in a forgotten age of great technological advancement and spiritual wisdom, declining into periods of increasing violence and spiritual degeneracy, which will now be remedied by the emergence of an Age of Aquarius, from which the milieu gets its name. There is also a strong focus on healing, particularly using forms of alternative medicine, and an emphasis on unifying science with spirituality.

The dedication of New Agers varied considerably, from those who adopted a number of New Age ideas and practices to those who fully embraced and dedicated their lives to it. The New Age has generated criticism from Christians as well as modern Pagan and Indigenous communities. From the 1990s onward, the New Age became the subject of research by academic scholars of religious studies.