Initially expected to be released during the hiatus of her group Destiny's Child in 2003, recording of the album was accelerated after the success of the single "Dilemma," a collaboration with rapper Nelly.

Largely produced within three weeks only, guest appearances on Simply Deep include Nelly, Solange Knowles and Joe Budden.

The album received generally mixed to lukewarm reviews from most music critics who called it a pleasant listen but found that it lacked ambition.

While Simply Deep peaked at number 12 on the Billboard 200 and sold over 600,000 copies in the United States,[2] it was regarded as a bigger commercial success abroad, where it topped the UK Albums Chart,[3] reached the top five in Australia, Denmark, and Ireland, and singles such as "Stole" and "Can't Nobody" were released to stronger commercial success.

[9] Issued to major success, "Dilemma" became a worldwide number-one hit that year, allowing Rowland's label Columbia Records to advance the release date of Simply Deep from 2003 to late 2002.

[16] In addition, she would work with Troy Johnson, Alonzo Jackson, Damon Sharpe, Billy Mann, Anders Barrén, and Jany Schella, and trio Steve Kipner, Dane Deviller, and Sean Hosein.

[16] Songwriter-producer Rich Harrison contributed "Can't Nobody," the first of many songs which he would produce for either Destiny's Child or the band's solo projects.

[25] "Stole" was released as the album's lead single in October 2002, following the worldwide success of "Dilemma", it entered the top twenty on the majority of the charts it appeared on but only a moderate hit compared to its predecessor.

But it's all done with style and intelligence, whether she's luxuriating in the loneliness of "Everytime You Walk Out That Door" or evoking the momentum of the first flush of love in "Train on a Track".

"[32] Joy Dunbar, writing for BBC Music, noted that while "the albums main weakness is that it tries to offer too much diversity and Kelly tries too hard to stand outside her former incarnation," it was a must-have for fans of R&B music, adding: "Simply Deep endeavours to demonstrate another side of Kelly Rowland, as a songwriter and an independent solo artist [...] The in frequent high points make this a must for your collection.

"[35] In her review for Simply Deep, Caroline Sullivan of The Guardian wrote, "Rowland is no longer a mere backing vocalist for Beyoncé Knowles.

"[31] He especially criticized Solange Knowles' contribution to the album, noting her "icky [and] laughable lyrics" as the worst on Simply Deep which he rated two and a half out of five stars.

[31] Jon Caramanica of Entertainment Weekly commented that "Rowland, at times, seems like Destiny's adopted child, never receiving a full helping of Knowles-family adulation.

"[33] Rolling Stone's Christian Hoard found that the album's "tired character sketches and polite R&B hooks will make you long for the sass and spirit of her main outfit.

[41] It was this week's fourth-highest charting entry after Santana's Shaman, Foo Fighter's One by One and Rod Stewart's It Had to Be You: The Great American Songbook.

[42] On December 5, 2002, Simply Deep was certified gold by the Recording Industry Association of America (RIAA) for shipments figures in excess of 500,000 copies.

[45] It received both a silver and a gold certification by the British Phonographic Industry (BPI) the following week, and on April 11, 2003, was certified platinum for sales of 300,000 units.