In 2016, the LIGO and Virgo Collaborations announced the first direct detection of gravitational waves, opening up a new window for astronomy and cosmology. David McClelland was a vital contributor to this success as Australia’s leading audio-band gravitational wave scientist and Chair of the Instrument Science/Advanced Detector program in the 1000-strong LIGO Scientific Collaboration. He led the ANU team that played a crucial role in designing, installing and commissioning Advanced LIGO’s acquisition system, which brings the interferometers into operation. His pioneering quantum science experiments that beat the previous low-frequency limit for squeezing light by three orders of magnitude were also essential for improving gravitational wave detection sensitivity.