Gibberellins (GAs) are pivotal phytohormones regulating fruit development, yet the molecular mechanisms by which they modulate strawberry fruit size and quality remain elusive. Here, we investigated the effects of exogenous GA₃ on the fruit development of the cultivated strawberry (Fragaria × ananassa ‘Benihoppe’). Treatment with 20 mg/L GA₃ significantly promoted fruit enlargement, advanced ripening by 7 days, and increased fruit weight and dimensions. Integrated transcriptomic and targeted metabolomic analyses revealed that GA₃ application induced a substantial reprogramming of the endogenous hormone landscape, notably triggering a significant increase in auxin (IAA) levels. Transcriptome profiling identified numerous differentially expressed genes (DEGs), with KEGG enrichment analysis highlighting the “plant hormone signal transduction” pathway as the most significantly enriched. Further analysis pinpointed key DEGs involved in auxin signaling (AUX/IAA, ARF, GH3, and SAUR) and gibberellin perception (GID1), suggesting a central role for auxin-mediated processes in GA₃-induced fruit expansion. We propose that exogenous GA₃ promotes strawberry fruit development through a synergistic mechanism: (1) enhancing the biosynthesis of endogenous bioactive GAs; (2) activating auxin signal transduction pathways to drive cell expansion; and (3) attenuating the repression of DELLA proteins. Our study unveils the critical role of the GA₃-IAA signaling axis in strawberry fruit development, providing a theoretical foundation for harnessing hormone regulation to improve fruit yield and quality in strawberry production.