Actor-turned-director Dexter Fletcher has also signed on to helm the film, reported Digital spy.
Fletcher made his directorial debut with 2011's 'Wild Bill'. He recently completed work on the musical film 'Sunshine on Leith', based on The Proclaimers' songbook.
The biopic will centre around Mercury's formative years, culminating with the band's headline performance at Live Aid in 1985. It will not deal with the singer's death due to AIDS-related complications in 1991.
Whishaw will next be seen in Ron Howard's Heart of the Sea and will reprise his role as Q in the next James Bond film.