Manufacturing accounts for more than three-quarters of US corporate patents. The competitive shock to this sector emanating from China’s economic ascent could in theory either augment or stifle US innovation. Using three decades of US patents matched to corporate owners, we quantify how foreign competition affects domestic innovation. Rising import exposure intensifies competitive pressure, reducing sales, profitability, and R&D expenditure at US firms. Accounting for confounding sectoral patenting trends, we find that US patent production declines in sectors facing greater import competition. This adverse effect is larger among initially less profitable and less capital-intensive firms.