The influence of Poisson’s ratio ( ν) on the thickness-dependent stress concentration factor (SCF) along the root of elliptic holes in elastic plates subjected to tension is systematically investigated by use of three-dimensional finite element method. It is found that the thickness-dependent maximum of SCF, ( K t ) max, increases significantly with increasing ν. As the thickness to root radius ratio B/ ρ grows from 0.1 to 1000, the ( K t ) max undergo a peak value, which can be increased 9% for a circular hole and 23% for an elliptic hole with length of short to long axial aspect ratio t = 0.1 when ν increases from 0.1 to 0.49. It is also found that the peak value occurs in a narrow range of the thickness to elliptic short axis ratio B/ b (2–3) with different t and ν. When B/ ρ is high enough, an increase of ν from 0.1 to 0.49 leads to decreasing in the SCFs on the free surface ( K t ) surf about 24% and 61% and increasing in the ratio of ( K t ) max/( K t ) surf about 38% and 195% for circular hole and elliptic hole with t = 0.1. The ν-dependent empirical formulae of the relationships among ( K t ) max, ( K t ) surf and the corresponding planar solution ( K t ) p− σ have been obtained by fitting the numerical results with satisfied accuracy, which will be useful for strength and fatigue designs of engineering structures with notches and holes.