Value of the data •This data presents phenotypic assessments of MDA-MB-231 cells within hydrogel formulations with varying matrix adhesivity and crosslink density with respect to single cell dormancy, balanced dormancy and metastatic growth, which can guide other researchers toward designing intelligent synthetic matrices for studying tumor dormancy. •For future investigations, proteomic and genomic characterization of cell populations in the classified phenotypic states can provide clues that distinguish specific dormancy signature of cancer cells from those of metastatic populations. •The phenotypic classification method employed in this study could be extended towards other cancer cell types (breast, prostate, colon, liver etc.) and patient-derived xenografts.