Birgit Koschischek (born May 22, 1987 in Vienna) is an Austrian swimmer, who specialized in sprint freestyle and butterfly events.
She is a two-time Olympian, a four-time Austrian long and short course record holder, and a member of Schwechat Swimming Club (German: Schwimmverein Schwechat) in Schwechat, under her personal coach Adam Thoroczkay.