A wheel bearing apparatus for a vehicle comprising: an outer member to be fitted into a knuckle forming a suspension apparatus of a vehicle and formed on its inner circumference with double row outer raceway surfaces (10a, 10a); an inner member formed on its outer circumference with inner raceway surfaces (2a, 3a) opposing respectively to one of the double row outer raceway surfaces (10a, 10a); double row rolling elements (7, 7) freely rollably contained between the inner raceway surfaces and the outer raceway surfaces (2a, 3a and 10a, 10a) of the inner member and the outer member; and seals (8, 9 (20, 23)) mounted within annular openings formed between the outer member and the inner member, wherein the inner-side seal (9 (20, 23)) of the seals (8, 9 (20, 23)) comprises an annular slinger and a sealing plate (12), the slinger comprising a cylindrical portion to be press-fitted onto the inner member and standing portion extending radially outward from the cylindrical portion, and the sealing plate (12) comprising a core metal to be press-fitted into the inner circumference of the end of the outer member and a sealing member (14) integrally adhered to the core metal via vulcanizing adhesion, and characterized in the sealing member (14) having a pair of side lips (14a, 14b) angularly extending radially outward and adapted to be slide-contacted with the standing portion of the slinger via a predetermined axial interface; that the sealing member (14) is secured to the core metal with extending over the outer circumference of the end of the core metal; and that the sealing member (14) is formed with an outer circumferential lip extending radially outward from its circumferential end, having a substantially L-shaped longitudinal section and adapted to be fitted in a gap between the inner-side end of the outer member and a flange portion of the knuckle such that a tip end portion of the outer circumferential lip and a lip apex of the outer circumferential lip elastically contact, via predetermined interferences after assembly of the wheel bearing apparatus onto the knuckle, with two points, respectively, a chamfered portion between the outer circumference and the end face of the outer member and a flange of the knuckle, to surely prevent bulging out of the outer circumferential lip from the knuckle. an outer member to be fitted into a knuckle forming a suspension apparatus of a vehicle and formed on its inner circumference with double row outer raceway surfaces (10a, 10a); an inner member formed on its outer circumference with inner raceway surfaces (2a, 3a) opposing respectively to one of the double row outer raceway surfaces (10a, 10a); double row rolling elements (7, 7) freely rollably contained between the inner raceway surfaces and the outer raceway surfaces (2a, 3a and 10a, 10a) of the inner member and the outer member; and seals (8, 9 (20, 23)) mounted within annular openings formed between the outer member and the inner member, wherein the inner-side seal (9 (20, 23)) of the seals (8, 9 (20, 23)) comprises an annular slinger and a sealing plate (12), the slinger comprising a cylindrical portion to be press-fitted onto the inner member and standing portion extending radially outward from the cylindrical portion, and the sealing plate (12) comprising a core metal to be press-fitted into the inner circumference of the end of the outer member and a sealing member (14) integrally adhered to the core metal via vulcanizing adhesion, and characterized in the sealing member (14) having a pair of side lips (14a, 14b) angularly extending radially outward and adapted to be slide-contacted with the standing portion of the slinger via a predetermined axial interface; that the sealing member (14) is secured to the core metal with extending over the outer circumference of the end of the core metal; and that the sealing member (14) is formed with an outer circumferential lip extending radially outward from its circumferential end, having a substantially L-shaped longitudinal section and adapted to be fitted in a gap between the inner-side end of the outer member and a flange portion of the knuckle such that a tip end portion of the outer circumferential lip and a lip apex of the outer circumferential lip elastically contact, via predetermined interferences after assembly of the wheel bearing apparatus onto the knuckle, with two points, respectively, a chamfered portion between the outer circumference and the end face of the outer member and a flange of the knuckle, to surely prevent bulging out of the outer circumferential lip from the knuckle.