Yellow is the color between green and orange on the spectrum of visible light. It is evoked by light with a predominant wavelength of roughly 570–590 nm. In traditional color theory, used in painting, and in the subtractive color system, used in color printing, yellow is a primary color. In the RGB color model, used to create colors on television and computer screens, yellow is a secondary color made by combining red and green at equal intensity.

The word yellow comes from the Old English geolu, geolwe (oblique case), meaning "yellow, yellowish", derived from the Proto-Germanic word gelwaz "yellow". It has the same Indo-European base, gʰel-, as the words gold and yell, or "cry out."

According to surveys in Europe, Canada, and the United States, yellow is the color people most often associate with amusement, gentleness, and spontaneity, but also with duplicity, envy, jealousy, avarice, and, in the U.S., with cowardice. In Iran it has connotations of pallor/sickness, but also wisdom and connection. It plays an important role in Asian culture, particularly in China, where it is seen as the color of happiness, glory, wisdom, harmony, and culture.