Environmental shareholder activism at publicly traded companies in the U.S. features some of the largest investors in the world supporting proposals sponsored by some of the smallest investors in the world. From 2015 to the present, most environmental shareholder proposals were brought to annual meetings of companies by relatively unknown investment groups such as As You Sow, Mercy Investment Services, The Park Foundation, Trillium Asset Management, Calvert Asset Management, The Unitarian Universalist Association of Congregations and the Presbyterian Church of the USA. Only occasionally have these proposals been co-sponsored or sponsored by significantly larger pension funds in the U.S. market known for their interests in corporate environmental policy. With these proposals, these small investors have commanded degrees of attention at corporations highly disproportionate to their usually miniscule ownership stakes. The 2017 proxy season is likely to bring continued increases in visibility for these investors, with added support from a few of the world’s leading asset managers.