Siana was a female Cardassian who lived on Cardassia Prime in the late-24th century.
In early 2375, she met Legate Damar at a dinner held in honor of Legate Hovat. He later took her back to Dominion Headquarters where they both shared a glass of Kanar while looking at Dominion War fleet movements.
Soon after, Weyoun entered, telling Damar that he would have her executed if she remained. Upon leaving, Weyoun told Damar that Siana was "a pleasant woman." (DS9: "Shadows and Symbols")
Siana was played by actress Lori Lively in her only Star Trek appearance.
The script for "Shadows and Symbols" simply describes Siana as "an attractive CARDASSIAN FEMALE."