Phenylhydrazine and its van der Waals complexes with one or two argon atoms were investigated with theoretical calculations and resonant two photon ionization (R2PI) spectroscopy. The ab initio and DFT calculations found a conversion of the orbital hybridization of the N_β atom from sp³-like in the S₀ state to sp²-like in the S₁ state, suggesting that the lone pair electrons of the N_β atom are involved in a super p-p–π conjugation over the skeleton of phenylhydrazine in the S₁ state. The structural change of the hydrazino group in the S₁← S₀ electronic transition was reflected by the vibrational excitations of the hydrazino group observed in the 1C-R2PI spectrum. The band origin of the S₁← S₀ transition is determined to be 33610 cm⁻¹ and the adiabatic ionization energy (IE) of phenylhydrazine, measured by 2C-R2PI spectroscopy, is 62829 ± 15 cm⁻¹. The S₁← S₀ electronic transitions of phenylhydrazine–Ar and phenylhydrazine–Ar₂ complexes were also observed in the 1C-R2PI spectrum, and their band origins are, respectively, red-shifted by 39 and 80 cm⁻¹ from that of phenylhydrazine.