A new distinct cultivar of Campanula plant named `ROYAL`, characterized by its upright, compact, rounded plant habit; plant spread measuring about 22 cm; purple-violet colored mature petals (upper surface: RHS N82B); green colored mature leaves (upper surface: RHS N137A); cordate leaves with an acute tip; short internode measuring about 11 mm; and sepal texture that is dull, with short stiff hair on margin with abaxial side.