Sets of magnetoelastic equations in the quasi‐magnetostatic approximation and in the absence of dissipation are deduced for uniaxial antiferromagnets of the easy‐axis type on the basis of a previously set forth fully nonlinear, rotationally invariant, thermodynamically admissible theory of deformable ferrimagnets. The equations are obtained for three typical initial magnetic configurations where the bias field is either parallel or orthogonal to the easy axis and depending on whether this field is weak, moderate or strong relatively to some combinations of material parameters. In each case, the linearization about the initial configuration (which is automatically endowed with initial fields and internal stresses) is performed by means of the so‐called Lagrangian variation of the nonlinear field and constitutive equations. In the process of linearization, all elastic, magnetic, and magnetoelastic coefficients evaluated at the initial state are given a thermodynamical definition. The linearization about a finite initial state allows one to exhibit the various influences of this state on the linearized equations and the alterations brought on the material‐coefficient tensors (stiffening of the elasticity coefficients, symmetry breaking by the bias magnetic field, magnetoelastic coupling at any order since the linearization is made with a fully nonlinear theory as starting point).