The Big Five personality traits is a suggested taxonomy, or grouping, for personality traits, developed from the 1980s onward in psychological trait theory.

Starting in the 1990s, the theory identified five factors by labels, for the US English speaking population, typically referred to as:

• openness to experience (inventive/curious vs. consistent/cautious)
• conscientiousness (efficient/organized vs. extravagant/careless)
• extraversion (outgoing/energetic vs. solitary/reserved)
• agreeableness (friendly/compassionate vs. critical/rational)
• neuroticism (sensitive/nervous vs. resilient/confident)

When factor analysis is applied to personality survey data, it reveals semantic associations: some words used to describe aspects of personality are often applied to the same person. For example, someone described as conscientious is more likely to be described as "always prepared" rather than "messy". These associations suggest five broad dimensions used in common language to describe the human personality, temperament and psyche.

Those labels for the five factors may be remembered using the acronyms "OCEAN" or "CANOE". Beneath each proposed global factor, there are a number of correlated and more specific primary factors. For example, extraversion is typically associated with qualities such as gregariousness, assertiveness, excitement-seeking, warmth, activity, and positive emotions. These traits are not black and white, but rather placed on continua.