List of world under-20 records in athletics

World U20 records in the sport of athletics are ratified by World Athletics. Athletics records comprise the best performance of an athlete before the year of their 20th birthday. Technically, in all under 20 age divisions, the age is calculated "on December 31 of the year of competition" to avoid age group switching during a competitive season. These age category records were formerly referred to as world junior records.

Outdoor
Key:

h = hand timing a = automatic timing + = en route to longer distance X = unratified due to inadequate doping control OT = oversized track (> 200m in circumference)
 * 1) = not officially ratified by World Athletics