Explore the future developments and applications of Post-Newtonian theory in gravitational wave astronomy through this 20-minute conference talk delivered at the International Centre for Theoretical Sciences. Delve into the theoretical framework that provides crucial approximations for understanding gravitational wave sources and their detection, examining how Post-Newtonian methods continue to evolve in the era of advanced gravitational wave observatories. Learn about the current challenges and promising research directions in this field as part of a comprehensive discussion meeting celebrating the 10th anniversary of gravitational wave detection, featuring leading experts exploring the transformative impact of gravitational wave astronomy on modern physics and astrophysics.