Dea Herdželaš (born 7 November 1996) is a Bosnian professional tennis player.
Herdželaš achieved a career-high singles ranking of world No. 183 on 23 May 2022, and reached a best doubles ranking of 334 in June 2023. As a junior, she had a best combined ranking of world No. 82, which she achieved on 21 January 2013.
Herdželaš made her debut for the Bosnia and Herzegovina Fed Cup team in February 2013, losing to Anne Keothavong of Great Britain.
Herdželaš won the 2012 Serbian national team championships with TK Partizan, winning each of her three singles matches.
Partnering Nefisa Berberović, she won the silver medal in the women's doubles at the 2018 Mediterranean Games, losing to Turkish pair Başak Eraydın and İpek Öz in the final which went to a deciding champions tiebreak.
Herdželaš has reached 19 career singles finals posting a record of nine wins. Additionally, she has reached 23 career doubles finals (7 titles). All of her finals both singles and doubles have come on the ITF Circuit.