The theory of force‐free magnetic fields is applied to equilibrium configurations of an incompressible fluid with axisymmetric motions. It is demonstrated that solutions satisfying collinear force‐free flow satisfy the vorticity equation for zero viscosity. Experimental measurements of the magnetic and flow fields of the plasmoids generated by a conical &thgr;‐pinch plasma gun are shown to be in agreement with the solutions to these equations.