The room temperature formation of GaP(110) interfaces with the transition metals (TM) vanadium and yttrium were studied by photoemission spectroscopy. Both the evolution of band bending and the interface chemical reactivity were deduced from the Ga 3dand P 2pcore level emission spectra for a metal coverage range of ∼0.003 to 50 Å. Free Ga is generated through a TM–Ga exchange reaction; it disperses in both metals with increasing coverages and with a noticeable tendency toward surface segregation. Two phosphorous reaction components were observed for both metals, one of which was attributed to free P, the other to TM–P bonding. Band gap emission attributed to an impurity state derived from the V 3dlevel was observed for coverages as low as 0.01 Å. A metallic Fermi edge developed at 1 Å of V, but required a thickness of ∼30 Å for Y. However, metallic character was observed in the replaced Ga for Y coverages ≳3 Å. The band bending for both metals onn‐GaP is characterized by a near‐constant value of the Fermi levelEFclose to midgap for a broad coverage range to ∼1 Å, followed by a rapid drop ofEFwith onset of metallicity in the V. For Y, this decrease extended to coverages beyond 20 Å, consistent with the delayed onset of metallicity for this system. Schottky barrier heights of 1.33 eV (V) and 1.24 eV (Y) were measured. For coverages below the onset of metallicityEFappears to be determined by the observed TM‐induced impurity states in the gap. The previously described delocalization model successfully accounts for both the observed drop inEFwith onset of metallicity and Schottky barrier heights for a number of metals, including V and Y.