The grime artist has confirmed his Friday night appearance on the Pyramid Stage on Instagram.
The University of Oxford has taken "responsibility for missing an opportunity" after denying it rejected Stormzy's scholarship offer.
The rapper paid a visit to his old school on A-levels results day.
Justin Welby said he is keeping the line: "I stay prayed up and get the job done", in his thoughts.
Stormzy used his Brit Awards performance to launch an attack on Theresa May and her Government over the Grenfell Tower tragedy.
Stormzy has used his set at Glastonbury to call attention to the recent Grenfell disaster and demand answers over what happened.
The grime artist stepped in to help a student fulfill her dream of studying of Harvard in a gesture that she said left her "shell-shocked".