A facile ethylene glycol–based solvothermal method was developed for the synthesis of lanthanide orthovanadate LnVO4 (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm, Yb, Lu) nanoparticles with relatively uniform size and morphologies. The LnVO4 nanoparticles ranged from 100 to 500 nm and changed from spheres to ellipses and platelet–shaped particles depending on the ionic size. Radius of the Ln ions affected crystal structure. The particles with larger ions form monoclinic-type structure for LaVO4 and with smaller ions form zircon-type structure for LnVO4 (Ln = Pr-Yb). A nucleation and aggregates formation mechanism of LnVO4 nanomaterials was proposed to illustrate the crystal growth. The morphologies of LnVO4 nanoparticles could be turned by pH value and molar ratio of reactants. Spherical LaVO4 and PrVO4 nanoparticles were obtained at pH 6, whereas elliptical nanoparticles were obtained at pH 3. Eu3+-, Dy3+-, and Sm3+-doped zircon-type YVO4 nanoparticles exhibit strong luminescence typical of doped ions.