Nadia Ali (born August 3, 1980) is an American singer and songwriter. Ali gained prominence in 2001 as the frontwoman and songwriter of the group iiO after their debut single "Rapture" gained significant success in Europe, most notably the United Kingdom, where the song peaked at number two on the UK Singles Chart in November 2001. Their 2006 single, "Is It Love?", reached the top of the Billboard Hot Dance Club Play chart.

After embarking on a solo career in 2005, Ali became a vocalist in electronic dance music. She released her debut album Embers in 2009. Three singles from the album reached the top-ten of the Billboard Hot Dance Club Play chart, including the No. 1 hit, "Love Story".

In 2010, Ali released a remix album series titled Queen of Clubs Trilogy to mark her decade-long career as a singer. "Rapture" was re-released as the only single from the trilogy and the song was once again a chart success in Europe. Ali released the single "Pressure" with Starkillers and Alex Kenji in 2011, which became a club and festival anthem and received an International Dance Music Award. In 2012, she collaborated with BT and Arty on the single "Must Be the Love". She released the song "Almost Home" with Sultan + Shepard in 2017, which reached No. 4 on the Billboard Dance/Mix Show Airplay chart and received a Juno Award nomination.

In 2018, she debuted a new direction and sound under the experimental project titled HYLLS, which saw her departing from electronic dance music toward the indie pop genre.

In 2022, she collaborated with Michael Calfan and released a song titled "3, 2, 1".

Nadia Ali was born in Tripoli, Libya to Pakistani parents on August 3, 1980. The family relocated when she was five years old and she was subsequently raised in Queens, New York City.

Ali started working in the New York offices of Versace when she was 17. A colleague from Versace introduced her to producer Markus Moser, who was looking for a female-singer (or "chanteuse") to collaborate on some of his original productions for a girl group in Germany. The two teamed up with Moser working on production, while Ali wrote the lyrics and vocals for the songs. Her first song was the single "Rapture", which she wrote in 30 minutes based on an encounter with an Australian nightclub patron. A demo of the song was first played at the New York club Twilo in 2001 and received early support from influential DJ Pete Tong who played the demo on his show on BBC Radio 1. The song eventually became an Ibiza favorite after support from prominent DJs such as Sasha, Danny Tenaglia and Sander Kleinenberg during the summer season. Released in late 2001 by Ministry of Sound, the single became a commercial success peaking at No. 2 on the UK Singles Chart and Billboard's Hot Dance Club Play chart, while charting in several countries in Europe. The success of "Rapture", Ali said, caused the formation of iiO as the music they were initially working on was quite different from dance music and were asked to come up with a project name to promote the single. They originally named themselves Vaiio after the Sony VAIO laptop Ali used to write the lyrics on. The duo toured internationally and released several more singles, including "At the End", "Runaway", "Smooth", and "Kiss You". Their first studio album, Poetica followed in 2005.

Ali left the group in 2005 to pursue a solo career, while Moser continued to release iiO material featuring her on vocals. Most notably, these releases include the 2006 single "Is It Love?" (which reached No. 1 on the Billboard Hot Dance Club Play chart), the 2007 remix album Reconstruction Time: The Best of iiO Remixed and the 2011 studio album Exit 110.