Junior world records in athletics

World Junior Records in the sport of athletics are ratified by the International Association of Athletics Federations. 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.

Key:   Awaiting ratification   not an IAAF record event   will not be ratified by IAAF
ht = hand timing
a = automatic timing
+ = to longer distance
# = not officially ratified by IAAF
X = unratified due to inadequate doping control
OT = oversized track (> 200m in circumference)

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