We have investigated the spectroscopy and photochemistry of Zn+(C2H4) in an angular reflectron time-of-flight mass spectrometer. We identify four absorption bands in the spectral range 220-550 nm. These bands are assigned to radiative transitions in the bimolecular complex correlating with Zn-centered and ethylene-centered absorptions, and with Zn-ethylene photo-induced charge transfer processes. The lowest energy band, assigned as 1 B-2(2)<--1 (2)A(1), is a weak continuum consistent with a large geometry change and fast predissociation. The higher energy 1 B-2(1)<--1 (2)A(1) band shows a long progression in the intermolecular stretch with a mode frequency of omega (e)=333.7 cm(-1). The spectroscopic results, including partially resolved rotational structure, are consistent with a weakly bound, pi -bonded complex in C-2v symmetry. A Birge-Sponer analysis gave an estimate for the dissociation energies of the excited 1 B-2(1) state as D-e(')=2.76 eV and the ground 1 (2)A(1) state as D-e(')=0.86 eV. A second structured band at still higher energies is tentatively assigned as 2 B-2(2)<--1 (2)A(1) and shows activation of higher frequency intramolecular ethylene modes. Zn+ and C2H4+ fragment ions are observed over most of the spectral range. At higher energies (lambda < 250 nm) we also see a significant branching to reactive products C2H2+ and C2H3+ that result from charge transfer accompanied by C-H bond cleavage. We propose a reaction mechanism that involves coupling through an excited charge-transfer state followed by C-H bond insertion.