Think about smartphone, HDTV, video conferencing, CT medical imaging, remote sensing, …  Can you name one technology that underpins all of them? Signal processing (SP) is considered by many as a set of ubiquitous technologies yet often hidden from plain sight, which have transformed the digital world and changed our lives in numerous ways. SP as a field is supported by mathematical theories and coupled with physical, engineering, and other domain-specific insights. The digital SP (DSP) took off in the mid-1960s, aided by the advancement of integrated circuit and digital computers, and has since then made profound impacts on society.  With its root traced back to 75 years ago, the IEEE Signal Processing Society (SPS) is the world’s premier professional society for SP scientists and professionals. Through its high-quality publications, conferences, and technical and educational activities, the SPS has played a pivotal role in advancing the theory and applications of SP, and in building the global SP community.   This talk will reflect on the 75-year journey of signal and data science. After a general overview, I will zoom in on a few examples from information forensics and security (IFS), an interdisciplinary area that SPS took the leadership in fostering the advancement and community building in the new millennium.