A deluxe edition of This Is Acting was released on 21 October 2016 featuring seven new tracks, including solo and Kendrick Lamar-assisted versions of the single "The Greatest".

[5][6] She also revealed that the success of 1000 Forms of Fear, specifically its lead single "Chandelier",[7] encouraged her to continue releasing new material, and said of the album's title: "I'm calling it This Is Acting because they are songs I was writing for other people, so I didn't go in thinking 'this is something I would say'.

[10] Shortly after Sia's announcement, Out published a list of her "10 Greatest Hits for Other Artists" in anticipation of the album.

[11] During an online chat with fans in April 2015, Sia revealed that the album would "probably" be released in early 2016, but possibly before the end of 2015.

On 7 November 2015, Sia performed "Alive" and "Bird Set Free" on Saturday Night Live; the episode was hosted by Donald Trump.

[23] A deluxe edition of This Is Acting was released on 21 October 2016 featuring seven new tracks, including three brand new tracks: "Confetti", "Midnight Decisions", and "Jesus Wept", as well as the single remix of "Cheap Thrills", the Alan Walker remix of "Move Your Body", and the solo and Kendrick Lamar-assisted versions of "The Greatest".

[24] In September 2015, Sia confirmed the album's lead single "Alive" would be released later that month and was originally written for Adele; the English singer and songwriter co-wrote but "rejected" the song at the last minute.

[27] "Cheap Thrills" was released as the album's second official single on 17 December 2015, and it was originally planned for Rihanna.

[30] "Unstoppable" was released as the sixth and final single from the album on 18 July 2022, after gaining traction over the years from usage in commercials and TikTok videos.

Jessie Morris of Complex commented that the song sounds like a "page torn right out of Demi Lovato's Confident book", while editors of other media platforms like Idolator noticed this as well, which raised speculation that the track was intentionally written for Lovato.

Club gave the album a favorable review, stating that "There's a clear theme here, and it's emancipation—from fear, from doubt, and most of all, from feeling as though she wasn’t meant to be a star.

"[50] Jon Pareles from The New York Times gave the album a mixed review, writing "In 'Alive', as she repeats 'I'm still breathing!'

Even as she and her producers flaunt their layered vocals and whiz-bang sound effects, there are already so many of Sia's midtempo victim-to-victory anthems around that they offer diminishing returns, particularly when listened to as an album.

"[51] Kathy Iandoli of Idolator was more positive towards the effort, stating that it "feels like the aftermath of coming to terms with her nagging demons, as Sia maintains brutal honesty cloaked in cinematic, mainstream music — albeit through songs that, as we well know by now, were written for and rejected by other artists."

She started in the super cool indie world, moved over to mid-level pop majesty, took a break to be a hit songwriter and then slid into near-icon status.

"[52] This Is Acting debuted atop the ARIA Albums Chart in Australia, and received a gold certification for sales of over 35,000 copies.