Socially responsible investing (SRI) is any investment strategy which seeks to consider financial return alongside ethical, social or environmental goals. The areas of concern recognized by SRI practitioners are often linked to environmental, social and governance (ESG) topics. Impact investing can be considered a subset of SRI that is generally more proactive and focused on the conscious creation of social or environmental impact through investment. Eco-investing (or green investing) is SRI with a focus on environmentalism.

In general, socially responsible investors encourage corporate practices that they believe promote environmental stewardship, consumer protection, human rights, and racial or gender diversity. Some SRIs avoid investing in businesses perceived to have negative social effects such as alcohol, tobacco, fast food, gambling, pornography, weapons, fossil fuel production or the military. Socially responsible investing is one of several related concepts and approaches that influence and, in some cases, govern how asset managers invest portfolios. The term "socially responsible investing" sometimes narrowly refers to practices that seek to avoid harm by screening companies for ESG risks before deciding whether or not they should be included in an investment portfolio. However, the term is also used more broadly to include more proactive practices such as impact investing, shareholder advocacy and community investing. According to investor Amy Domini, shareholder advocacy and community investing are pillars of socially responsible investing, while doing only negative screening is inadequate.

Measuring social, environmental and ethical issues is nuanced and complex and depends on needs and context. Some rating companies have developed ESG risk ratings and screens as a tool for asset managers. These ratings firms evaluate companies and projects on several risk factors and typically assign an aggregate score to each company or project being rated.

The origins of socially responsible investing (SRI) may date back to the Religious Society of Friends (Quakers). In 1758, the Quaker Philadelphia Yearly Meeting prohibited members from participating in the slave trade—buying and/or selling humans.

One of the most articulate early adopters of SRI was John Wesley (1703–1791), one of the founders of Methodism. Wesley's sermon "The Use of Money" outlined his basic tenets of social investing: not to harm your neighbor through your business practices and to avoid industries like tanning and chemical production, which can harm the health of workers. Some of the best-known applications of socially responsible investing were religiously motivated. Investors would avoid "sinful" companies, such as those associated with products such as firearms, liquor, and tobacco.

The modern era of socially responsible investing evolved during the socio-political climate of the 1960s. During this time, socially concerned investors increasingly sought to address equality for women, civil rights, and labor issues. Economic development projects started or managed by Martin Luther King, such as the Montgomery bus boycott and the Operation Breadbasket Project in Chicago, established the early model for socially responsible investing efforts. King combined ongoing dialog with boycotts and direct action targeting specific corporations. Concerns about the Vietnam War were further incorporated by some social investors. An iconic image from the era was a picture in June 1972 of a naked nine-year-old girl, Phan Thị Kim Phúc, screaming and running towards a photographer, her back burning from the napalm dropped on her village. That photograph channeled particular outrage against Dow Chemical, the manufacturer of napalm, and prompted protests across the country against Dow Chemical and other companies seen as profiting from the Vietnam War.

During the 1950s and 1960s, trade unions deployed multi-employer pension fund monies for targeted investments. For example, the United Mine Workers fund invested in medical facilities, and the International Ladies' Garment Workers' Union (ILGWU) and International Brotherhood of Electrical Workers (IBEW) financed union-built housing projects. Labor unions also sought to leverage pension stocks for shareholder activism on proxy fights and shareholder resolutions. In 1978, SRI efforts by pension funds was spurred by The North will Rise Again: Pensions, Politics, and Power in the 1980s and the subsequent organizing efforts of authors Jeremy Rifkin and Randy Barber. By 1980, presidential candidates Jimmy Carter, Ronald Reagan and Jerry Brown advocated some type of social orientation for pension investments.

SRI had an important role in ending the apartheid government in South Africa. International opposition to apartheid strengthened after the 1960 Sharpeville massacre. In 1971, Reverend Leon Sullivan (at the time a board member for General Motors) drafted a code of conduct for practicing business in South Africa which became known as the Sullivan Principles. However, reports documenting the application of the Sullivan Principles said that US companies were not trying to lessen discrimination in South Africa. Due to these reports and mounting political pressure, cities, states, colleges, faith-based groups and pension funds throughout the US began divesting from companies operating in South Africa. In 1976, the United Nations imposed a mandatory arms embargo against South Africa. From the 1970s to the early 1990s, large institutions avoided investment in South Africa under apartheid. The subsequent negative flow of investment eventually forced a group of businesses, representing 75% of South African employers, to draft a charter calling for an end to apartheid. While the SRI efforts alone did not bring an end to apartheid, it did focus persuasive international pressure on the South African business community.