The 2005 South American Youth Championship (Sudamericana sub-20) was a football competition contested by all ten U-20 national football teams of CONMEBOL.

The tournament was held in Colombia between 13 January and 6 February 2005, it was the 22nd time the competition has been held and the third to take place in Colombia.

Colombia finished undefeated, winning their second trophy.

The three top competitors advance to a single final group of six, wherein each team plays five matches.

The top four teams in the final group qualify to the 2005 FIFA World Youth Championship For a list of all the squads in the final tournament, see 2005 South American U-20 Championship squads.