An expansion bolt comprises a bolt having an end-face anchoring means for the tension-resistant anchoring of the bolt on or in a first assembly part, which bolt has a truncated-cone-shaped cone section and a bolt threaded section in its end section opposite to the anchoring means with a nut screwed thereon, an expansion sleeve having a cylindrical lateral surface and an inner cone contour interacting with the cone section of the bolt, and a clamping device supported on a second assembly part for widening the expansion sleeve and applying an axial clamping force to the assembly parts to be connected together. The cone section of the bolt is tapered in the direction toward its anchoring means and the inner cone contour of the expansion sleeve is tapered in the same direction. The expansion sleeve bears a clamping flange protruding outward in the radial direction on its end opposite to the inner cone contour. The clamping device comprises a clamping ring having an axial passage opening. The expansion sleeve engages through this passage opening, permitting an adjustability of the expansion sleeve in relation to the clamping ring in the axial direction, and protrudes with its clamping flange beyond a peripheral region of the clamping device enclosing the passage opening. The clamping ring also comprises multiple pressure bolts arranged circumferentially distributed, which mesh with their thread in internally threaded holes extending through the clamping ring in the axial direction and act with their bases indirectly or directly against the second assembly part to widen the expansion sleeve and apply an axial clamping force to the assembly parts. Furthermore, a connection assembly having such an expansion bolt is described.