To clarify the role of the AhGRF gene in the growth and development of Amaranthus hypochondriacus, we identified the members of its gene family utilizing the latest genomic data, followed by a comprehensive analysis of their sequences and response patterns to exogenous gibberellin. The results showed that nine genes including AhGRF1-AhGRF9 were identified and they were unevenly distributed on eight chromosomes and can be divided into five subfamilies, with different AhGRF genes exhibiting distinct expression patterns and the vast majority being highly expressed in floral organs. The promoter regions of AhGRFs contained response elements for hormones such as salicylic acid, abscisic acid, methyl jasmonate, gibberellin, and auxin, as well as stress-related elements like those induced by drought and low temperature; promoters of AhGRF2, AhGRF5, AhGRF6, AhGRF8 also carried functional elements associated with endosperm expression, meristem development and palisade mesophyll cell differentiation. Furthermore, gibberellin treatment significantly promoted leaf and stem growth. Except for AhGRF8, which was not expressed in leaves and stems, the expressions of AhGRF7 and AhGRF9 in leaves were suppressed, while the expressions of AhGRF1-AhGRF6 were upregulated at different time points. In stems, relative expressions of all genes were upregulated at 1 hour after gibberellin treatment, displaying a rhythmic expression pattern in multiple genes, which differed from their expression profile in leaves.