Viviana Grădinaru (born 1981) is a Romanian-American neuroscientist who is Professor of Neuroscience at the California Institute of Technology. She develops technologies for brain imaging, including optogenetics and CLARITY, to understand reward and sleep. She has been awarded the Presidential Early Career Award for Scientists and Engineers and the National Institutes of Health Director's Pioneer Award. In 2019 she was a finalist for the Blavatnik Awards for Young Scientists. In 2020 she was awarded a Vilcek Prize for Creative Promise in Biomedical Science by the Vilcek Foundation.