The band spent two years recording the album, in three different cities, and frontman Jason Pierce spent another year mixing it at home. Spiritualized previewed the record live, playing it in its entirety during a show at the Royal Albert Hall on 11 October 2011.Sweet Heart Sweet Light featured contributions from Pierce's 11-year-old daughter Poppy Spaceman, as well as contributions from the Icelandic band Amiina. Jason Pierce revealed in an interview that the album will "embrace" more poppy songs. Jason Pierce also stated that the album was partly inspired by the experiences of performing Ladies and Gentlemen We Are Floating in Space live in its entirety.
Sweet Heart Sweet Light was originally going to be called Huh? Pierce was taking medication for liver disease while writing the album and the original title was a reference to the effects the medicine had on Pierce's mind.
The first song released from the album was "Hey Jane." A music video for "Hey Jane" was released on 19 March 2012. The video has caused controversy over its violent content.
Sweet Heart Sweet Light has received critical acclaim. From a collected 38 reviews, the review website Metacritic gives the album a score of 81 out of 100, indicating "Universal Acclaim."
Nathan Shaffer of Tiny Mix Tapes gave the album a perfect score, writing "[..] Sweet Heart, Sweet Light is one of those gorgeous things and, if nothing else, the most profound late statement Spaceman has given us in a decade."Pitchfork's Ryan Dombal gave the album a "Best New Album" designation, calling it Pierce's most uplifting album of his career. In another positive review, BBC Music's Chris Lo wrote "For every diehard fan there's someone else wondering what all the fuss is about. Sweet Heart Sweet Light, Spiritualized's seventh studio album, isn’t going to change any of that." Lo concluded: "...it's a Spiritualized album, and a great one." Rob Hakimian also praised the album, writing "All ten of the songs here are grandiose and muscular in the great tradition of Spiritualized songs, doing away entirely with the fragility that cropped up on songs like "Death Take Your Fiddle" from their last album."
Not all reviews were positive. In a more mixed review, Drowned in Sound's Didz Hammond wrote: "It is, all in all, a pretty solid front half of a Spiritualized album that sort of transmits intermittently in the middle and then totally falls on its arse for the last three tracks." Harry Sword of The Quietus gave the album a negative review, writing "Not only does Sweet Heart Sweet Light hit all patented Spiritualized thematic buttons squarely between the eyes – religion, drugs, sickness and redemption – it is also a record that covers everything with a Wyoming sized scoop of full-fat icky sentiment." Sword concluded: "And where previous lyrical excesses have often been tempered by a genius for tension building arrangement, the overriding vibe on Sweet Heart Sweet Light is that of bloated self-parody, and gratuitous self-pity."
The album was listed 20th on Stereogum's list of top 50 albums of 2012.