Freemasonry or Masonry refers to fraternal organisations that trace their origins to the local guilds of stonemasons that, from the end of the 13th century, regulated the qualifications of stonemasons and their interaction with authorities and clients. Modern Freemasonry broadly consists of two main recognition groups:

• Regular Freemasonry insists that a volume of scripture be open in a working lodge, that every member profess belief in a Supreme Being, that no women be admitted, and that the discussion of religion and politics not take place within the lodge.
• Continental Freemasonry consists of the jurisdictions that have removed some, or all, of these restrictions.

The basic, local organisational unit of Freemasonry is the Lodge. These private Lodges are usually supervised at the regional level (usually coterminous with a state, province, or national border) by a Grand Lodge or Grand Orient. There is no international, worldwide Grand Lodge that supervises all of Freemasonry; each Grand Lodge is independent, and they do not necessarily recognise each other as being legitimate.

The degrees of Freemasonry retain the three grades of medieval craft guilds, those of Entered Apprentice, Journeyman or fellow (now called Fellowcraft), and Master Mason. The candidate of these three degrees is progressively taught the meanings of the symbols of Freemasonry and entrusted with grips, signs, and words to signify to other members that he has been so initiated. The degrees are part allegorical morality play and part lecture. These three degrees form Craft (or Blue Lodge) Freemasonry, and members of any of these degrees are known as Freemasons or Masons. There are additional degrees, which vary with locality and jurisdiction, and are usually administered by their own bodies (separate from those who administer the Craft degrees).

Due to Freemasonry's tradition of not discussing its rituals with non-members, the fraternity has become associated with many conspiracy theories.