Portugal's first participation in the Summer Olympic Games took place at the 1912 Summer Olympics in Stockholm, Sweden. The nation was represented by a delegation of six competitors, who took part in three sports but failed to win a medal. The Portuguese debut participation was marked by the death of flag bearer Francisco Lázaro, who succumbed to electrolytic imbalance after the marathon race.

4 athletes represented Portugal in the nation's Olympic debut. Lázaro collapsed during the marathon due to his use of wax to prevent sweating; he died the next morning.^[1]

Ranks given are within that athlete's heat for running events.

A single fencer represented Portugal in that nation's Olympic debut. Fernando Correia was disqualified in the first round of the épée competition.

• Fernando Correia (chief of mission)