安娜塔西亚（英语：Anastacia，1968年9月17日—）原名安娜塔西亚·林恩·纽柯克（Anastacia Lyn Newkirk）是美国的创作型女歌手。

她在欧洲、亚洲、大洋洲与南非的知名度与在美国本土相比都高得多，至2005年她已在全球销售超过两千万张专辑。她锐利且深情的歌声与其矮小的身材形成鲜明的对比，有“The Little Lady with The Big Voice”（大声的小女人）之称。她所戴的深色商标眼镜是她的标志之一，不过她已于2005年8月通过手术永久矫正视力，取下了那副眼镜。

Anastacia Lyn Newkirk (born September 17, 1968) is an American singer-songwriter, producer and former dancer. She is best known for her pop music of the early 2000s which had a significant impact in Europe and Oceania. Her first two albums Not That Kind (2000) and Freak of Nature (2001) were released in quick succession to major success. Spurred on by the multi-platinum, global smash "I'm Outta Love", Anastacia was awarded as the 'World's Best-Selling New Female Pop Artist' in 2001. Her commercial appeal continued with international hits such as "Paid My Dues", One Day In Your Life and the official song of the 2002 FIFA World Cup, "Boom". After recovering from cancer, she returned with 2004's Anastacia which deviated from previous albums into pop-rock. Peaking at number one in 11 countries, it became Europe's second biggest selling album of the year. Its lead "Left Outside Alone" remained at number one on the European Billboard chart for 15 weeks and helped Anastacia launch the most successful European tour by a solo artist that same year. In 2005, the multi-platinum compilation project Pieces of a Dream was released which spawned the chart topping duet with Eros Ramazzotti, "I Belong to You (Il Ritmo della Passione)". Anastacia established herself as one of the top selling international female pop-singers of the 2000s before taking a hiatus in late 2006. She has sold over 30 million records worldwide and has topped the U.S. dance chart on two separate occasions. She is one of the most successful female pop stars of the millennium.