Before the advent of the electric guitar, the guitar was defined as an instrument characterised by a long, fretted neck, flat wooden soundboard, ribs, and a flat back, most often with incurved sides. Instances of musical instruments similar to the guitar have been found to date back as far as 4,000 years ago. The roots of the guitar can be traced back thousands of years to instruments found in central Asia and India and is distantly related to instruments such as the tanbur and setar, and the Indian sitar.

The modern Engish word, guitar, evolved from Spanish guitarra (German Gitarre, French Guitare), also loaned from the medieval Andalusian Arabic qitara, itself derived from the Latin cithara, which in turn came from the earlier Greek word kithara, a possible descendant of Old Persian sihtar.

The Romans brought their cithara to Hispania around 40 AD and it is from this instrument that the modern guitar is descended. Further adaptations and developments were made when teh Moors introduced their four-string oud in the eighth century. In other European locations the Scandinavian six-string lute became popular wherever the Vikingstravelled. In many 800 AD carvings, the Norse hero Gunther can be seen playing a lute with his toes as he lay dying in a snake pit.

By 1200 AD, the four string "guitar" had evolved into two types: the guitarra morisca (Moorish guitar) which had a rounded back, wide fingerboard and several soundholes, and the guitarra latina (Latin guitar) which resembled the modern guitar with one soundhole and a narrower neck.

Another important influence on the development of the guitar is the Spanish vihuela. The "viola da mano" is a 15th century guitar like instrument that had lute-style tuning and a guitar-like body.

The Vinaccia family of luthiers is known for developing the mandolin, and may have built the oldest surviving six string guitar.