The 'All Night Long' hitmaker and Scottish superstar will top the bill at the annual music extravaganza held at Seaclose Park in Newport, Isle of Wight, on Friday, June 12.
Lionel, who has never played the legendary festival before, said: ''I'm excited to be playing at The Isle of Wight Festival next summer. ''It's the first time I've performed at the festival and I can't think of a better way to start the summer!
''It's a festival steeped in music history - Jimi Hendrix, Bob Dylan, The Rolling Stones have all headlined and I'm honoured to be joining the esteemed list! See you all there.''
Whilst 'Grace' hitmaker Lewis, who is planning to party hard after his set, said: ''Buzzing to be playing The Isle of Wight Festival next year!! Going to try and keep the other day clear so I can get a few scoops in after I play! See ya next year yaaaaaaas (sic)''
Also playing on the Friday is Pete Tong, who will put on his 'Pete Tong Presents Ibiza Classic' dance show, and singer/songwriter Becky Hill.
Saturday, June 13, will see Irish chart-toppers Snow Patrol close the main stage, along with The Chemical Brothers, who will also make their debut at the IOW Festival.
'Play God' hitmaker Sam Fender and James Arthur are also performing on the main stage.
Duran Duran will play their only UK festival date, closing the festival on Sunday, June 14.
They are joined by Dido and the recently reunited Supergrass.
Also playing across the festival are Example, Happy Mondays, JC Stewart, Kaiser Chiefs, Maisie Peters, Primal Scream, Shed Seven, Sigma (DJ set) and The Manor.
Happy Mondays frontman Shaun Ryder said: ''The Isle of Wight is such a great festival - we're really looking forward to being back there again in 2020!!''
More acts will be confirmed in due course.
Tickets for The Isle of Wight Festival 2020 go on sale this Friday (06.12.19) at 9am www.isleofwightfestival.com/tickets