This study explores the existence, diversity, mechanisms, and economic implications of peer effects on the green innovation behaviour of corporations, based in the theories of imitation and peer influence. Leveraging panel data from Chinese manufacturing firms for the years 2015 to 2020, we implement a spatial autoregressive model within the industrial sphere to construct a causally interconnected framework. The results suggest that the green innovation behaviour of corporations is significantly influenced by their peers, with a noticeable positive spatial spillover effect. Moreover, we investigate heterogeneity through the lens of regional characteristics and enterprise size. Extended analysis reveals that while financing constraints exert a substantial negative moderating effect, the moderating influence of market-incentive environmental regulation appears to be minimal. Additionally, the positive repercussions of peer corporate green innovation behaviour on corporate sustainability performance underscore that such interactions are predominantly synergistic rather than competitive.