| Damjanov, Ivana | Structural Evolution of Quiescent Galaxies from the Peak of the Cosmic Star Formation Epoch | 2011 | University of Toronto | GMOS-N | Canada |
| Dahm, Scott E. | The evolution of young clusters | 2005 | University of Hawaii | GMOS-N | USA |
| Dage, Kristen C. | Long term optical and X-ray mointoring of black hole candidates in extragalactic globular clusters | 2020 | Michigan State University | GMOS-S | USA |
| da Silva, Patricia | Nuclei of the Milky Way morphological twins: a complete sample of 10 objects | 2020 | University of San Paulo | GMOS-S | Brazil |
| D'Andrea, Christopher Brian | Testing supernova cosmology and progenitor effects with the SDSS-II supernova survey | 2011 | University of Pensylvania | GMOS-S | USA |
| Cypriano, Eduardo Serra | Lentes Gravitacionais em Aglomerados de Galaxias | 2002 | University of Sao Paulo | GMOS-N | Brazil |
| Cuneo, Virginia | Sistemas binarios interactuantes con componentes compactas | 2017 | Universidad Nacional de Cordoba | GMOS-N/GMOS-S | Argentina |
| Cucchiara, Antonino | Gamma-ray burst afterglows as probes of their host galaxies and the cosmos | 2010 | The Pennsylvania State University | GMOS-N/GMOS-S/NIRI | USA |
| Crabtree, Kyle Nicholas | Chemical physics and astrochemistry of H+3 and sub Doppler mid infrared spectroscopy of molecular ions | 2012 | University of Illinois at Urbana-Champaign | PHOENIX | USA |
| Couto, Guilherme dos Santos |
Feeding and feedback in radio galaxies of the local universe | 2016 | Universidade Federal do Rio Grande do Sul | GMOS-N/GMOS-S | Brazil |
| Courtney, Nathan James | X-ray luminous clusters of galaxies at z>0.3 | 2003 | Durham University | GMOS-N | UK |
| Cottis, Christopher Euan | BALQSOs in SDSS: On the absence of Observational Evidence for Ly-??N V line-locking and a discussion of the physical conditions within BAL outflows | 2010 | University of Leicester | GMOS-N | UK |
| Cook, Jason Campbell | Dissecting intermediate-sized Kuiper belt objects | 2007 | Arizona State University | NIRI+ALTAIR | USA |
| Collinson, James S. | Spectral and temporal studies of supermassive black holes | 2016 | Durham University | GNIRS | UK |
| Collado, Ana | Estrellas Wolf-Rayet de tipo WN en la Via Lactea | 2013 | Universidad Nacional de San Juan | GMOS-S | Argentina |
| Cochetti, Yanina | Estructura y propiedades físicas de envolturas circunestelares en estrellas Be | 2019 | Universidad Nacional de La Plata | GNIRS | Argentina |
| Coatman, Liam | A near-infrared view of luminous quasars: black hole masses, outflows and hot dust | 2017 | University of Cambridge | GNIRS/NIRI | UK |
| Childress, Michael Joseph | Host galaxies of type ia supernovae from the nearby supernova factory | 2011 | University of California Berkeley | GMOS-S | USA |
| Chilcote, Jeffrey Kaplan | Direct observation of extrasolar planets and the development of the gemini planet imager integral field spectrograph | 2014 | University of California, Los Angeles | GPI | USA |
| Chhetri, Rajan | Quasars, Radio Galaxies and Gravitational Lenses in the High Radio Frequency Universe | 2012 | University of New South Wales | GMOS-S | Australia |
