Tuned Mass Dampers (TMDs) are widely used in structural engineering to mitigate undesired vibrations caused by environmental loads such as wind and earthquakes. This study presents an experimental investigation into the dynamic performance of a TMD system integrated into a 10-story scaled steel shear frame model subjected to both harmonic and seismic excitations. The experimental setup includes a servo-motor-driven shake table and a vision-based measurement system to monitor structural response. The TMD, comprising a 1.1 kg suspended mass tuned to a specific frequency, was evaluated under six different loading scenarios—including El Centro, Kobe, Kocaeli, and Northridge earthquake records. Results show that the TMD is highly effective in reducing peak displacements and accelerations under harmonic excitation and provides variable yet beneficial damping under seismic loads, depending on the input frequency content. The findings confirm the potential of TMDs as a passive yet powerful solution for enhancing structural resilience in both service and extreme load conditions.