Ellie Goulding is set to perform at BBC Sound Of 2019 Live on January 31 with Octavian.
The 'Close To Me' singer received the prestigious honour in 2010, and she will join this year's recipient and the runners-up Dermot Kennedy, Grace Carter Mahalia and Sea Girls for a performance on the show, which will be broadcast on BBC Radio 1.
Sharing her excitement for the gig, Ellie tweeted: "I'm so excited to be playing at BBC #SoundOf2019 live alongside some incredible new talent. Hope to see you there too! x http://bbc.in/2D9b6xz (sic)"
French-British star Octavian - whose real name is Oliver Godji - became the first rapper in 15 years, when 50 Cent topped the annual poll, to win the title.
Reacting to the news, he said: "That's lit. I don't even know how to feel right now ... Mum, I made it!"
A panel of 136 music experts, including Radio 1 DJs, artists such as Ellie and 2018's winner Sigrid came together to narrow down the finalists and pick the overall winner.
Octavian - who released his 2018 mixtape 'Spaceman' to critical acclaim in September - has previously been compared to Drake and even received the praise of the 'In My Feelings' hitmaker for his dancehall-influenced sound, and he's vowed to make 2019 a "loud" year for his music.
Octavian said: "I get inspired and I try to make a new sound every day. It's going to be a very loud year for me. Loads of music, loads of visuals, loads of albums."
King Princess, 'Why Her Not Me' hitmaker Grace, slow thai and Rosalía also made the top five.
Dermot, Ella Mai, Flohio, Mahalia
and Sea Girls were also contenders in the longlist.
Annie Mac, who unveiled the winner on her BBC Radio 1 show, commented: "BBC Sound Of is always a wonderful opportunity to get a snapshot of the new music landscape in the UK and this year is really interesting. 6 of the 10 artists are women. And we have two rappers in the top five! I am delighted that UK rap music has got such great placement in the list - Octavian is a truly original and exciting artist, pushing the boundaries of the genre and it's great to see such a progressive artist getting such a huge accolade."