Manipulating ferroic orders and realizing their coupling in multiferroics at room temperature are promising for designing future multifunctional devices. Single external stimulation has been extensively proved to demonstrate the ability of ferroelastic switching in multiferroic oxides, which is crucial to bridge the ferroelectricity and magnetism. However, it is still challenging to directly realize multi‐field‐driven magnetoelectric coupling in multiferroic oxides as potential multifunctional electrical devices. Here, novel magneto–electric–optical coupling in multiferroic BiFeO3‐based thin films at room temperature mediated by deterministic ferroelastic switching using piezoresponse/magnetic force microscopy and aberration‐corrected transmission electron microscopy are shown. Reversible photoinduced ferroelastic switching exhibiting magnetoelectric responses is confirmed in BiFeO3‐based films, which works at flexible strain states. This work directly demonstrates room‐temperature magneto–electric–optical coupling in multiferroic films, which provides a framework for designing potential multi‐field‐driven magnetoelectric devices such as energy conservation memories. The magneto–electric–optical coupling is realized in multiferroic BiFeO3‐based films at room temperature by engineering ferroelastic switching. The reversible ferroelastic switching is ubiquitous in BiFeO3‐based films with flexible strain states and domain patterns, which is determined by the photoinduced electric field and symmetry mismatch in films. This work provides a framework for multi‐field‐driven magnetoelectric memories with low power consumption.