Defender Boly and striker Afobe both enjoyed successful loan spells at Molineux last season, from Porto and Bournemouth respectively.
They are now staying with Nuno Espirito Santo's side for the upcoming Premier League campaign after options in those loan agreements were triggered.
It is understood Boly and Afobe have each been snapped up for £10million.
A £13million deal for Diogo Jota, who also shone during a loan spell from Atletico Madrid, takes Wolves' summer spending to £33million.
Frenchman Boly made 37 appearances last term and proved to be a key player in the Championship title triumph.
Afobe re-joined the club, on a temporary basis, from the Cherries in January and chipped in with six goals in 16 appearances.
Portuguese youngster Jota scored 17 goals in 44 league games last season.
All three are all set to be involved as Nuno's squad starts pre-season training on June 27.