Transition metal perovskite oxides display a variety of emergent phenomena that can be tuned by tailoring the oxygen octahedral rotation. SrRuO₃, a ferromagnetic perovskite oxide, is well-known to display various atomic structures with different octahedral distortions when grown as thin films. With angle-resolved photoemission spectroscopy and electron diffraction techniques, we study the electronic structure of SrRuO₃ thin films as a function of the film thickness. Octahedral distortions on the surface can be qualitatively estimated based on intensity ratio between different bands. Our results shed light on how structural variation and transition may be understood in terms of photoemission spectroscopy data.