The two bands both have outstanding back catalogues with more than 20 combined UK top 10 hits, including If You Tolerate This Your Children Will Be Next and The Masses Against The Classes from Manic Street Preachers and Too Much Too Young and the legendary Ghost Town from The Specials.
George Akins, owner of festival organisers DHP Family, said: "Manic Street Preachers and The Specials are two legendary bands and have made a huge mark on the UK music scene.
"We're delighted to have them both with us on the main stage at Splendour celebrating two very special anniversaries.
"The crowd can expect a belter set of some of their greatest hits."
Manic Street Preachers were in high demand by Splendour fans, bagging the top spot of who they'd like to see at the festival in a survey conducted by DHP Family.
Throughout the Welsh rockers' illustrious career they have headlined several festivals including Reading and Leeds, Glastonbury, T in the Park, and V Festival and gained a host of music accolades including 11 NME Awards, eight Q Awards and four BRIT Awards.
As well as their triple-platinum album This Is My Truth Tell Me Yours, the band have had 13 UK top 10 albums, including Everything Must Go and their latest album, Resistance Is Futile.
This will be the group's first Nottingham appearance since their 2007 Rock City show.
The Specials are one of the most electrifying, influential and important bands of all time and return to Splendour hot on the heels of a special 40th anniversary tour celebrating their formation and the two-tone label.
Formed in Coventry in 1977, the trend-starting ska revival band hit the British music scene hard. In the UK their debut single Gangsters reached number six in the UK chart and every subsequent single was a top ten hit, including two number ones - Too Much Too Young and Ghost Town, which was named 1981's single of the year by NME, Melody Maker and Sounds.The Manics and The Specials are the first of more than 40 acts who will perform at this year's festival with further big name announcements to come.To stay in touch with festival news visit the website or follow Splendour on Facebook at @splendourfestivalUK, on Twitter at @splendourfest or on Instagram at @splendourfest