Bolasie is expected to join from Everton after choosing Villa over Championship rivals Middlesbrough.
Netherlands international El Ghazi, meanwhile, is on course to arrive from Lille on a season-long loan deal, with an option to buy.
The 23-year-old, a client of super agent Jorge Mendes, began his senior career at Ajax, before moving to France in January last year.
El Ghazi, who has been deemed surplus to requirements by Lille boss Christophe Galtier, was linked with a possible move to AC Milan during the January transfer window.
His arrival at Villa will come as a huge boost to manager Steve Bruce, who has been desperate to strengthen his team in wide areas.
Bolasie heads to Villa Park aiming to kick-start his career after a frustrating, injury-blighted two seasons at Everton following a £25million move from Crystal Palace.
The 29-year-old held talks with Boro boss Tony Pulis on Monday, before heading south to meet Bruce on Tuesday.