The Schiff base H2L, namely 2‐(3‐methoxysalicylidene‐amino)‐benzyl‐alcohol, 1 and its two pseudo‐polymorphs H2L⋅CH3OH 2 and H2L⋅H2O 3, have been synthesized by the condensation reaction of 2‐aminobenzyl alcohol and o‐vanillin in different solvents. X‐ray crystallographic analysis revealed that the keto‐enol tautomerism of H2L in solid state exists as a complex system of three different enol, keto and zwitterionic forms in equilibrium, dependent on crystal packing forces and the crystallization solvent. The enol, keto and mixed enol‐zwitterionic (roughly 1:1) forms were observed in the crystal structures of 1, 2 and 3, respectively. The crystallographic results are supported by FTIR and DFT calculations. Photophysical properties were determined in acetonitrile solution and solid state and were supported by TD‐DFT studies.