In the present work, potassium titanyl phosphate single crystals doped with different levels of Ge4+, Zr4+, and Ce4+ were successfully grown by flux using the top-seeded solution growth (TSSG) method. Their saturation temperatures and crystal habits were compared with those of the undoped single crystals and some differences were observed. In addition, the distribution coefficients of the different dopants were also determined and found to be in correlation with the ionic radii of the M4+ ions. Zr4+ doping gives the most suitable distribution coefficient, does not introduce problematic absorption bands in the visible region, and significantly reduces the ionic conductivity in the c direction,