Knitting is the process of interlooping yarn to create textile fabric made of interconnected loops, done by hand, machine or both.

Knitting creates stitches: loops of yarn in a row; the loops are created with a pair of knitting needles, which can either be straight and cylindrical or in the round with (often times plastic) tubes joining the ends of both. There are usually many active stitches on the needle at one time. Knitted fabric consists of a number of consecutive rows of connected loops that intermesh with the next and previous rows. As each row is formed, each newly created loop is pulled through one or more loops from the prior row and placed on the 'gaining needle' (the needle that is receiving newly created stitches) so that the loops from the prior row can be pulled off the other needle without unraveling.

Differences in yarn (varying in fiber type, weight, uniformity and twist), needle size, and stitch type allow for a variety of knitted fabrics with different properties, including color, texture, thickness, heat retention, water resistance, and integrity. A small sample of knitwork is known as a swatch and helps the maker determine the gauge of the intended work.

There are several origins of the word knit and knitting which include the German derivation from the word "knutten" (to tie), the Old Norse word "knytja", and the Old English words "cnyttan" (to tie a knot, bind together, fasten by tieing) and cnotta (knot).

Nålebinding (Danish: literally "binding with a needle" or "needle-binding") is a fabric creation technique predating both knitting and crochet.

Knitting is believed to be an evolution of the ancient craft of nålbinding, the Norwegian word for “needle binding.” Artifacts of this form of fabric making have been found in many regions including Egypt, China, Denmark, and Sweden, dating as far back as 4200 B.C.E. In nålbinding, fabric is created through forming loops and knots of yarn with a single needle. The exact origins of the invention knitting are unknown, however the earliest known examples are cotton socks dating from the 11th century, found in the remains of the city of Fustat, now part of Cairo.

The first commercial knitting guilds appear in Western Europe in the early fifteenth century (Tournai in 1429, Barcelona in 1496). The Guild of Saint Fiacre was founded in Paris in 1527 but the archives mention an organization (not necessarily a guild) of knitters from 1268. The occupation "cap knitter" was described Margaret Yeo, of London, in 1473 as these textile artists primarily produced knit caps and dyed stockings.

In 1589, William Lee of Nottinghamshire invented the first knitting frame, or stocking frame, which was an early form of the knitting machine. Lee petitioned Queen Elizabeth I for a patent but was denied due to the coarse nature of the frame-knit fabric and the fear that frame knitting would take away the jobs of hand knitters in England. Lee improved the knitting frame to accommodate a finer gauge, or number of stitches per inch, producing a smoother fabric, but his petition for a patent failed following the death of his court sponsor and apprentice, Lord Hunsdon, in 1596. Lee traveled to Normandy, France, and later Paris along with a group of apprentices in search of court sponsorship for his invention. After further trials and tribulations due to the assassination of King Henry IV in 1610, Lee was unable to establish a successful business in Paris. William Lee died in Paris in 1614, and his brother James Lee along with William's apprentice, Aston, adopted the petition to patent the knitting machine in England. By 1620, frame knitting was an established mode of production of knitted garments.