| Hoffmann, Samantha L. | Cepheid variables and their application | 2013 | Texas A&M University | GMOS-N | USA |
| Hoyer Miranda, Sergio David | Search for unseen planets using transit timing variations | 2012 | Universidad de Chile | GMOS-S | Chile |
| Hsieh, Henry H. | Comets amongst the asteroids: icy bodies in the inner solar system | 2007 | University of Hawaii | GMOS-N | USA |
| Hung, Li-Wei | Characterizing debris disks with multi-wavelength high-contrast imaging | 2016 | University of California Los Angeles | TRECS/GPI | USA |
| Indriolo, Nicholas | Investigating the cosmic-ray ionization rate in the galactic interstellar medium through observations of H3+ | 2011 | University of Illinois at Urbana-Champaign | PHOENIX | USA |
| Jasmim, Flávia Luzia | Estudo da composição superficial de diversas classes de pequenos corpos | 2013 | Observatorio Nacional | TRECS | Brazil |
| Jensen-Clem, Rebecca Marie | A Toolbox for Exoplanet Exploration | 2017 | California Institute of Technology | GPI | USA |
| Jiang, Linhua | Evolution of the quasar population at high redshift | 2008 | The University of Arizona | GNIRS/NIRI | USA |
| Johnson, Kelsey | The properties of super star clusters in a sample of starburst galaxies | 2001 | University of Colorado at Boulder | OSCIR | USA |
| Kalirai, Jasonjot | Astrophysics with white dwarfs | 2004 | University of British Columbia | GMOS-N | Canada |
| Kasliwal, Mansi M. | Bridging the gap: elusive explosions in the local universe | 2011 | California Institute of Technology | GMOS-N/GMOS-S/NIRI | USA |
| Kellogg, Kendra | Investigating Brown Dwarf Atmospheres: Gravity, Dust Content, Cloud Structure and Metallicity | 2017 | University of Western Ontario | GNIRS/FLAMINGOS-2/GMOS-S | Canada |
| Kennedy, Catherine R. | The history of chemical enrichment and the sites of early nucleosynthesis: CNO abundances of galactic carbon-enhanced metal-poor stars | 2011 | Michigan State University | GMOS-S/GMOS-N | USA |
| Kim, Jae-woo | Galaxy clustering and galaxy
clusters from the UKIDSS DXS | 2012 | Durham University | GMOS-N | UK |
| Knutson, Heather | Portraits of distant worlds: characterizing the atmospheres of extrasolar planets | 2009 | Harvard University | NIRI | USA |
| Krug, Hannah Bowen | Neutral gas outflows and inflows in local AGN & high-z Lyman-alpha emitters in COSMOS | 2013 | University of Maryland | GNIRS | USA |
| Kruger, Andrew James | Infrared Spectroscopy and Young Stellar Objects: Characterizing the Dust and Gas in Circumstellar Disks | 2011 | University of California Davis | PHOENIX/TRECS | USA |
| Kumari, Nimisha | Spatially-resolved studies of nearby star-forming galaxies | 2018 | University of Cambridge | GMOS-N | UK |
| Kynoch, Daniel | Spectral and temporal studies of accretion and ejection processes around supermassive black holes | 2019 | Durham University | GNIRS | UK |
| Lafreniere, David | Releve de planetes geantes autour d'etoiles proches par imagerie directe et optimisation d'une technique d'imagerie multibande | 2007 | Universite de Montreal | NIRI+ALTAIR | Canada |
