A weizza or weikza (Burmese: ဝိဇ္ဇာ, Pali: vijjādhara) is a mystic in Burmese Buddhism commonly associated with esoteric and heterodox practices such as recitation of spells, samatha, and alchemy. The goal of this practice is to achieve immortality and await the appearance of the future Buddha, Metteya.

Weikza practices are less common than merit-making practices or vipassanā meditation. During the socialist era from 1962 to 1988, Ne Win banned secret weizza associations, weizza magazines and literature, and portrayals of weizza from films and other media, but the concept has made a resurgence since 1988, particularly following the abolition of the national censorship board in 2012. Burmese pagodas often house weizza shrines, where they are venerated for their spiritual purity and their devotion to those in need. Weizza teachers have also amassed hundreds of thousands of followers using social media.

The word weizza (ဝိဇ္ဇာ) comes from the Pali word vijja, which means “knowledge” or “wisdom”, and is distantly related to the English word "wizard", as both stem ultimately from the Proto-Indo-European root *weyd-, meaning "to know or see".

Aside from epigraphs, there are no local Indic or vernacular compositions that have been securely dated to pre-Pagan Burma. However, there are some later attributions of texts that were written during the first millennium. One such example is the Kappālaṅkāra (ကပ္ပါလင်္ကာရ), a vijjādhara ("weikza") text said to have been written by the bhikkhu Uttamasīri during the first century CE. The text survives in an 18th-century Pali-Burmese nissaya version (which attributes the text to Uttamasīri in its colophon) compiled by Taungdwin Sayadaw Ñaṇābhidhammālaṅkāra.

In Myanmar, there are two classes of wizards; the sôns (စုန်း) and the weizza. The former are considered a bane to society, while the latter spend their days helping the common folk and undoing the curses brought upon by the sôns. The commonly known weizza known today first appeared during the Konbaung dynasty, when Bo Bo Aung, a monk in Sagaing, discovered manuscripts revealing the secrets of weizza. However, many recognized weizza today come from before the Konbaung dynasty. This was the last dynasty to rule Burma before colonial rule. Before weizza, there were the Zawgyi (ဇော်ဂျီ) and Yawgi (ယောဂီ). The Zawgyi were wizards who were written about in Burmese literature, while the Yawgi were Buddhist yogis who lead ascetic lives and wore brown robes. They followed eight to ten precepts of Buddhism, whereas most laymen follow five.

weizza are divided into four major orders:

Among these, the Than and In are considered the most powerful. The Pyada Weizza, or Mercury Wizards, also study alchemy in order to produce gold and silver from more common metals. The Than weizza are considered by their followers as masters of not only their subject, but also as medical advisors.

Among their powers, weizza possess the ability to see past lives, see and hear things that are far away, read minds, teleport, dive into the earth, walk on water, and be in multiple places simultaneously. Powerful practitioners of the weizza’s way are purported to live for centuries, even choosing the time of their next reincarnation. The In Weizza, who work with cabalistic squares, use one's birth date and time to create powerful charms and spells. In The Burman, Sir J. George Scott described some squares and charms so powerful that they could set a house ablaze. Others, engraved in stone and embedded in one's skin, would prevent drowning. Merely scratching an in in a house or tree could cause lightning to strike it.