The pair, played by Steve McFadden and Linda Henry respectively, will tie the knot on April 29 - the same day that Prince William and Kate Middleton are to marry at Westminster Abbey.
A source told The Mirror: "The royal wedding is the biggest event of this year and, for soap fans, Phil Mitchell is pretty close to royalty having been a favourite since he arrived in 1990. The show's bosses thought a wedding storyline would be perfect to coincide with William and Kate."
Phil is due to propose to Shirley on Monday after being rushed to hospital following a heart attack.
However, the weeks leading up to the ceremony will apparently be "riddled with drama" as Glenda Mitchell (Glynis Barber) threatens to reveal her affair with Phil.