The 1s(A1)2p0 and 2p transitions in Te donors in GaP have been observed. Together with similar data for Si and S donors, Faulkner's effective-mass (EM) calculations yield an ionization energy of 89.80.3 meV for Te donors. Conduction-band effective masses consistent with all the data for these GaP donors are m=(0.1800.005)m0 and mII=(1.50.2)m0. The effects of uniaxial stress on the "two-electron" transitions in the recombination of excitons bound to neutral Te donors in GaP are consistent with the final donor states observed being s-like with a valley-orbit splitting. © 1970 The American Physical Society.