Theodora Giareni (born 3 March 1990 in Marousi, Athens, Greece) is a Greek swimmer.

[1] At the 2012 Summer Olympics, she competed for the national team in the Women's 4 x 100 metre freestyle relay.

The team finished in 16th (last) place in the heats, failing to reach the final.

[2] She failed a doping control test was sent home from the 2016 Rio Olympic Games.

[4] This biographical article related to a Greek swimmer is a stub.