A strut assembly for a vehicle may include a shock absorber housing cover, into which a strut is inserted, and which is mounted, along with the strut, to a vehicle body, a shock absorber mounting panel configured to cover an upper portion of the shock absorber housing cover, and mounted to the vehicle body, and a coupling bolt inserted upward into a bolt coupling hole formed in the shock absorber housing cover, wherein the shock absorber mounting panel includes a contact surface portion having a cross-sectional area less than a cross-sectional area of a nut coupled with the coupling bolt, the contact surface portion having a hole corresponding to the bolt coupling hole, and the shock absorber mounting panel is brought into contact with the shock absorber housing cover by the contact surface portion.