Druidry, sometimes termed Druidism, is a modern spiritual or religious movement that promotes the cultivation of honorable relationships with the physical landscapes, flora, fauna, and diverse peoples of the world, as well as with nature deities, and spirits of nature and place. Theological beliefs among modern Druids are diverse; however, all modern Druids venerate the divine essence of nature. While there are significant variations in the expression and practice of modern Druidry, a core set of spiritual and devotional practices may be observed, including: meditation; prayer/conversation with deities and spirits; the use of extra-sensory methods of seeking wisdom and guidance; the use of nature-based spiritual frameworks to structure devotional practices and rituals; and a regular practice of nature connection and environmental stewardship work.

Neo-Druidry emerged in 18th-century Britain as part of the Romantic movement, which idealized the perceived spiritual wisdom and natural harmony of ancient Celtic societies. Early neo-Druids sought to emulate the Iron Age priestly class known as the druids, despite the limited and often speculative historical knowledge available at the time. As such, modern Druidic traditions are not directly descended from ancient practices, but rather are modern reconstructions or reinterpretations inspired by Romantic ideals and later scholarly and folkloric sources.

In the late 18th century, modern Druids developed fraternal organizations modeled on Freemasonry that employed the romantic figure of the British Druids and Bards as symbols of the indigenous spirituality of Prehistoric Britain. Some of these groups were purely fraternal and cultural, such as the oldest one that remains, the Ancient Order of Druids founded in 1781, creating traditions from the national imagination of Britain. Others, in the early 20th century, merged with contemporary movements such as the physical culture movement and naturism. Since the 1980s, some modern druid groups have adopted similar methodologies to those of Celtic Reconstructionist Paganism in an effort to create a more historically accurate practice. However, there is still controversy over how much resemblance modern Druidism may or may not have to the Iron Age druids.

By 2020, modern Druidry had spread to 34 nations, across 6 continents, and had taken root in 17 diverse biomes. The importance that modern Druids attributed to Celtic language and culture, circa 2020, varied depending upon the physical and cultural environments in which the individual Druid lived. By 2020, roughly 92% of world Druids were living outside the British Isles. While modern Druidry has spread rapidly across the globe, Druids do not proselytize, and 74% of world Druids actively work to keep their spiritual practices private.

Modern Druidry derives its name from the celtic magico-religious specialists of Iron Age Western Europe who were known as druids. There is no real historical continuity between the druids of Iron Age Europe and modern Druids. However, some Druids nevertheless regard modern Druidry as a genuine continuation of the practices of the Iron Age druids.

The 18th-century figure Iolo Morganwg fabricated what he claimed were early Welsh literary sources and traditions that supposedly dated to the prehistoric druids. Gorsedd, one of the 18th century traditions that were founded by Morganwg, became part of the National Eisteddfod of Wales festival. The concerns of modern Druidry, which include healing the planet, and seeking connections with the natural world, are likely very different from those of the Iron Age societies in which the original druids lived. Another 18th-century fabrication is the Fragments of Ancient Poetry, which was published by James Macpherson between 1760 and 1763. The poems were hugely popular; they were read by many of the notable figures of the period, including Voltaire, Napoleon, and Thomas Jefferson, and the quality of the poetry inspired contemporary comparisons with Homer. Though attributed to the ancient semi-legendary poet Ossian, the works are believed to have been composed by a wistful Macpherson seeking to recreate the oral traditions of Scotland.

Everything presently known about the Iron Age druids derives from archaeological evidence and Greco-Roman textual sources, rather than material produced by these druids themselves. Due to the scarcity of knowledge about the Iron Age druids, their belief system cannot be accurately reconstructed. Some Druids incorporate everything that is known about Iron Age druids into their practices. However, as noted by Irish contemporary paganism scholar Jenny Butler, the historical realities of Iron Age religion are often overlooked by Druids in favour of "a highly romanticised version".

Many Druids believe that the practices of the Iron Age druids should be revived and modified to meet current needs. In Ireland, some Druids have claimed that because the island was never conquered by the Roman Empire, the Iron Age druids survived here and their teachings were passed down hereditarily until modern times, at which modern Druids can reclaim them. Some Druids claim that they can channel information about the Iron Age druids.