Optical elastography techniques are rapidly emerging as preferred methods of measuring tissue mechanical properties due to a variety of benefits, such as resolution, speed, and noninvasive imaging. However, there remains a lack of research on the inter-operability of these methods, which makes inter-study and inter-method mechanical comparisons difficult. Therefore, this work aims to compare measurements obtained by various optical coherence elastography (OCE) techniques, Brillouin spectroscopy, and ultrasound-based shear wave elastography (USE) to the gold standard of uniaxial mechanical testing. This study utilized three sets of tissue-mimicking silicone phantoms with varying elasticities. We compared measurements of common optical elastography methods, including air-pulse OCE, aircoupled ultrasound OCE, reverberant OCE, and compression OCE, along with ultrasound elastography and Brillouin spectroscopy. The measurements from these methods were compared to the gold standard of uniaxial mechanical testing. The results of the quasistatic methods, i.e., mechanical testing and compression OCE, showed very good agreement for all three samples. The dynamic wave-based OCE and USE methods also had good inter-agreement, showing the inter-operability of air-pulse, air-coupled, and reverberant OCE and USE. Additionally, Brillouin spectroscopy measurements yielded the Brillouin frequency shift, which was able to discriminate all three sample sets. These results are the first step of a more robust framework for studying the relationship between mechanical measurements performed by various excitation methods.