Alexandra Caso Sierra (born April 25, 1987) is a volleyball player from the Dominican Republic, who competed for her native country at the 2004 Summer Olympics in Athens, Greece, wearing the number #6 jersey.
There she ended up in eleventh place with the Dominican Republic women's national team.
Caso played as a libero.
Playing with the Dominican Republic U-18 National Team, she won the "Best Libero", and the silver medal at the 2002 NORCECA Girls Youth Continental Championship U-18.She claimed the gold medal with the national squad at the 2003 Pan American Games.
Caso was named "Best Libero" at the 2005 NORCECA Championship.