After a year's hiatus from social media, Stormzy returned in early February 2017 via a series of billboard campaigns across London displaying the hashtag #GSAP 24.02. The album title was announced to be Gang Signs & Prayer. The album was released on 24 February 2017 and debuted at number one on the UK Albums Chart on 3 March 2017.
He has reached number one on the UK Singles Chart three times; firstly as part of "Artists for Grenfell" on 23 June 2017 with "Bridge Over Troubled Water", secondly with his own solo single "Vossi Bop", which debuted at number one upon its entry, ahead of "Me!" by Taylor Swift featuring Brendon Urie by some 500 combined sales, and thirdly with his collaboration with Burna Boy and Ed Sheeran, "Own It". Stormzy later released the singles "Crown", "Sounds of the Skeng" and "Wiley Flow", before announcing his second album, Heavy Is the Head, for release on 13 December 2019. Stormzy was recognised for both his contributions to music and his activism, landing him at number 5 in the Top 10 of the annual Powerlist in 2020, with an estimated net worth of £20 million in 2020.
On 24 June 2017, Stormzy performed a chant of "Oh, Jeremy Corbyn" to the tune of The White Stripes' Seven Nation Army on the Other Stage at the Glastonbury Festival. He also performed a rap he had written for the victims of the Grenfell Tower Fire, telling the festivalgoers to demand that the authorities "tell the... truth" and for the "Government to be held accountable". In September of that year, after being presented with the Solo Artist of the Year award by Corbyn at the GQ Men of the Year Awards, Stormzy called Theresa May a "paigon", a Jamaican Patois word used to describe an untrustworthy person. Later the same month, the conservative commentator Iain Dale placed Stormzy at Number 100 on his list of "The 100 most influential people on the Left", describing him as "Corbs' favourite Grime artist".
In November 2017, it was revealed that Stormzy had posted a series of messages on Twitter in 2011 that were deemed to be homophobic. These included a tweet where he referred to a gay character on the soap opera EastEnders as a "fucking fag". He also asked another user who was discussing using hair straighteners if they were a "fag" and urged his followers to "put on BBC1 this little black boy is a fucking fag". He later posted a series of tweets, stating: