Ana Carolina de Castro Muniz (born March 14, 1984) is a freestyle swimmer from Brazil.At the 1999 Pan American Games in Winnipeg, she won the bronze medal in the 4×200-metre freestyle.
She also finished 5th in the 400-metre freestyle, 6th in the 200-metre freestyle, and 6th in the 800-metre freestyle.In November 1999, she broke the short-course South American record of the 200-metre freestyle, with a time of 2:01.09.In December 1999, Muniz broke the South American record of the 800-metre freestyle, with a time of 8:48.53.In 1999, she was also South American record holder of the 400-metre freestyle, with a time of 4:16.32.At the 2000 FINA World Swimming Championships (25 m), in Athens, Muniz finished 9th in the 4×200-metre freestyle, where she broke the South American record, with a time of 8:18.87, along with Monique Ferreira, Tatiana Lemos and Paula Baracho.