The 54-year-old, from Blackburn, West Lothian, will receive the award for distinction in the field of music at a graduation ceremony on 30 June.
She described the honour, from the Glasgow music, drama, and dance academy, as a "great privilege".
Boyle has sold millions of albums since making her name on ITV's Britain's Got Talent in 2009.
She said: "I am truly honoured to be receiving this doctorate. It is brilliant and I thank the RCS for even considering me, let alone actually awarding me with this great privilege."
The singer has become a regular visitor at the RCS, working with Andrew Panton, artistic director of musical theatre.
Since 2012, he has vocally coached her on her studio albums as well as directed her sell-out UK and USA tours.
Other recipients of RCS honorary doctorates include singer Annie Lennox, actor and comedian Billy Connolly, actress Tilda Swinton, opera singer Dame Felicity Lott, actress Geraldine McEwan and stage and screen actor Timothy West.
Scottish singer Susan Boyle is to be awarded an honorary doctorate from the Royal Conservatoire of Scotland (RCS).