Alexandru Penciu (1 November 1932 – 11 August 2023) was a Romanian rugby union player and coach, who played as a fullback or centre.

Penciu was among the best players of his era, he was nicknamed "Alexander the Great" (Alexandru cel Mare) in his home country.

Penciu won 34 caps for Romania, from 1955 to 1967, and scoring 2 conversions, 7 penalties and 4 drop goals, 37 points in aggregate.

His last international game was on 10 December 1967 in Nantes in the 11–3 defeat against France in the FIRA Nations Cup, where he scored a penalty.

It was the second consecutive second-place finish for Romania in the competition, losing twice in a row the title to France, then the only continental European side at the Five Nations Championship.