| Spolaor, Max | Radial gradients in elliptical galaxies | 2009 | Swinburne University of Technology | GMOS-S | Australia |
| Stalder, Brian Adam | Adaptive optics studies of high redshift radio galaxies | 2007 | University of Hawaii | GMOS-N | USA |
| Steele, Matthew M. | The nature of the [O III] emission line system in the black hole hosting globular cluster RZ2109 | 2012 | Michigan State University | GMOS-S | USA |
| Stephens, Andrew W. | Stellar populations of nearby galaxies | 2001 | The Ohio State University | Hokupaa | USA |
| Stott, John Philip | The evolution of galaxies in massive clusters | 2007 | Durham University | GMOS-N | UK |
| Sutton, Andrew | Ultraluminous X-ray sources | 2013 | Durham University | GMOS-N | UK |
| Swinbank, Anthony Mark | Mapping the dynamics, star-formation rates, and chemical properties of galaxies with integral field spectroscopy | 2005 | Durham University | GMOS-N/GMOS-S | UK |
| Tam, Sut-Ieng | Mapping Dark Matter in Galaxy Clusters with Gravitational Lensing | 2020 | Durham University | GMOS-N | UK |
| Tang, Sumin | Exploring the Long-Term and Extreme Variability of Stars | 2012 | Harvard University | GMOS-N | USA |
| Tanner, Angelle Maria | Extended sources in the central parsec of the Galactic Center | 2004 | University of California, Los Angeles | Hokupaa | USA |
| Tehrani, Katie | Wolf-Rayet Populations in Local Group Metal Poor Galaxies | 2019 | University of Sheffield | GMOS-N/GMOS-S | UK |
| Tejos, Nicolas | The relationship between the intergalactic medium and galaxies | 2014 | Durham University | GMOS-S | UK |
| Teodoro, Mairan Macedo | Multi-spectral analysis of the cyclic events of Eta Carinae | 2009 | University of San Paulo | CIRPASS | Brazil |
| Thanjavur, Karunananth | Cosmic applications of Gravitational Lens Assisted Spectroscopy (GLAS) | 2009 | University of Victoria | GMOS-N/GMOS-S | Canada |
| Tobin, John J. | Morphologically complex protostellar envelopes: structure and kinematics | 2011 | The University of Michigan | NIRI | USA |
| Torres Zafra, Juanita | Spectro-photometric study of gamma-ray emitting blazars, their host galaxies and their environments | 2017 | Universidad Nacional de La Plata | GMOS-N/GMOS-S | Argentina |
| Toshikawa, Jun | Growth history of galaxy clusters traced by protoclusters at z~3-6 | 2015 | The Graduate University for Advanced Studies, Japan | GMOS-N | Japan |
| Trichas, Markos | Multi-wavelength surveys of extreme infrared populaitons | 2008 | Imperial College of London | GMOS-N | UK |
| Troutman, Matthew R. | Observing carbon monoxide in circumstellar disks | 2010 | Clemson University | PHOENIX | USA |
| Turri, Paolo | Advancing next generation adaptive optics in astronomy: from the lab to the sky | 2017 | University of Victoria | GeMS+GSAOI | Canada |
