The sixth South American Junior Championships in Athletics were held in Montevideo, Uruguay from October 9–14, 1966.

Detailed result lists can be found on the "World Junior Athletics History" website.

[1] An unofficial count yields the number of about 159 athletes from about 6 countries: Argentina (36), Brazil (36), Chile (33), Paraguay (11), Peru (22), Uruguay (21).

Medal winners are published for men[2] and women[3] Complete results can be found on the "World Junior Athletics History" website.

[1] * = another source[1] states rather: Hexathlon *   Host nation (Uruguay)