The boundary conditions are idealized in mechanics of materials. However, small imperfections may exist which deviate the conditions from being ideal. The non-ideal boundary conditions are modeled using perturbations and applied to buckling problems of columns. A linear and a nonlinear model are treated separately. The effect of such conditions on the critical loads and buckling shapes are analytically calculated using the strained parameter perturbation method. Depending on the mode numbers and the physical parameters, the critical loads may either decrease or increase. The mode shapes of the buckling are also distorted by the imperfections in the support conditions.