"I Need to Know" is a song by American singer Marc Anthony for his eponymous fourth studio album. It was released as the lead single from the album on August 16, 1999. Written and produced by Anthony and Cory Rooney, "I Need to Know" is a song about a man who longs to know how a woman feels about him. The song blends the musical styles of several genres, including R&B and Latin music; the instruments used include synthesized violin and piano sounds, timbales and congas. Anthony recorded a Spanish-language version of the song, translated by Angie Chirino and Robert Blades, titled "Dímelo".

Marco Antonio Muñiz, known professionally as Marc Anthony, is an American singer and songwriter. He is the top selling salsa artist of all time. A four-time Grammy Award, eight-time Latin Grammy Award and twenty-nine-time Lo Nuestro Awards winner, he has sold more than 12 million albums worldwide.