To lobby legislators, it is important for interest groups to signal their ability to help legislators win elections and provide them with policy-relevant information. We explore for-profit companies’ use of environmental, social, and governance (ESG) reports as a signaling device to promote their reputation to legislators and convey their ability to provide electoral and policymaking support, which is valuable for lobbying. To this end, we create a panel dataset by combining ESG reports issued by US companies and the same companies’ lobbying and campaign contribution records from 1999 to 2017. We expect companies to issue more ESG reports, as well as reports containing more quantitative content, when they lobby. The data conform to our expectations. We also reason that lobbying may be more strongly related to ESG reporting when it is coupled with campaign contributions made by affiliated corporate political action committees, but the data do not support this expectation.