Under visionary leadership of the Vice Chancellor Professor Dr. Robina Farooq, Department of Physics, Government College Women University Faisalabad, Pakistan has successfully conducted 3rd International Conference on Advances in Theoretical and Applied Physics (ATAP-2021) on February 24-26, 2021, on Zoom Meeting App. ATAP is a year-wise series of event where prominent scientists, researchers, scholars and industrialists from around the world join together to share their latest research results and ideas. Ms. Asma Khurshid, Head of Physics Department was the convener of the conference. Abstracts were invited for oral talks which covered several areas of applied and theoretical physics such as Materials Physics, Nanotechnology, Biomedical Physics, Composites Materials, Semiconductor, Fuel Cell and Energy Harvesting Materials, Magnetic, Optical and Photonic Materials, Polymers Science and Engineering, Laser and matter interaction, Photovoltaics, Membrane technology, Quantum Physics, Plasma Physics, computational Physics, and other related fields. Many renowned international delegates, scientists and researchers contributed in the conference from different corners of the globe like Canada, Brazil, UK, USA, Germany, Saudi Arabia, Qatar, China, Sweden, Turkey, etc. Many national speakers from University of the Punjab, COMSATS, PIEAS, GCUF, UAF, Azad Jamu and Kashmir University, and GCWUF also shared their innovative ideas and research work. This conference provided an ideal environment to develop new collaborations and meet experts of the mentioned fields.