Strontium is an element of fundamental importance in biomedical science. Indeed, it has been demonstrated that Sr2+ ions can promote bone growth and inhibit bone resorption. Thus, the oral administration of Sr-containing medications has been used clinically to prevent osteoporosis, and Sr-containing biomaterials have been developed for implant and tissue engineering applications. The bioavailability of strontium metal cations in the body and their kinetics of release from materials will depend on their local environment. It is thus crucial to be able to characterize, in detail, strontium environments in disordered phases such as bioactive glasses, to understand their structure and rationalize their properties. In this paper, we demonstrate that Sr-87 NMR spectroscopy can serve as a valuable tool of investigation. First, the implementation of high-sensitivity Sr-87 solid-state NMR experiments is presented using Sr-87-labeled strontium malonate (with DFS (double field sweep), QCPMG (quadrupolar Carr-Purcell-Meiboom-Gill), and WURST (wideband, uniform rate, and smooth truncation) excitation). Then, it is shown that GIPAW DFT (gauge including projector augmented wave density functional theory) calculations can accurately compute Sr-87 NMR parameters. Last and most importantly, Sr-87 NMR is used for the study of a (Ca,Sr)-silicate bioactive glass of limited Sr content (only similar to 9 wt %). The spectrum is interpreted using structural models of the glass, which are generated through molecular dynamics (MD) simulations and relaxed by DFT, before performing GIPAW calculations of Sr-87 NMR parameters. Finally, changes in the Sr-87 NMR spectrum after immersion of the glass in simulated body fluid (SBF) are reported and discussed.