Summary Regeneration starts with injury. Yet how injuries affect gene expression in different cell types, and how distinct injuries differ in gene expression remains unclear. We defined the transcriptomes of major cell types of planarians – flatworms that regenerate from nearly any injury – and identified 1,214 tissue-specific markers across 13 cell types. RNA sequencing on 619 single cells revealed that wound-induced genes were either expressed in nearly all cell types or specifically in one of three cell types (stem cells, muscle, or epidermis). Time-course experiments following different injuries indicated a generic wound response is activated with any injury regardless of the regenerative outcome. Only one gene, notum, was differentially expressed early between anterior- and posterior-facing wounds. Injury-specific transcriptional responses emerged 30 hours after injury, involving context-dependent patterning and stem-cell-specialization genes. The regenerative requirement of every injury is different; however, our work demonstrates that all injuries start with a common transcriptional response.