The partnership aims to create jobs and improve the health and well-being of '100 million people in Sub Saharan Africa and South Asia by 2025".
Transform is a five year, minimum £10 million investment initiative that will focus on water, sanitation and hygiene, with the potential to expand to household energy, the partnership said. The move is in support of global Sustainable Development Goals.
It will identify 'social business models' that help low-income households meet basic needs of water, sanitation, hygiene, and domestic energy, with a focus on digital and mobile.
The organisations' global teams based in Africa and South Asia will identify viable investments, provide capital, and deliver technical expertise.
Unilever is also engaging start-ups via its Unilever Foundry initiative, enabling 'social entrepreneurs' to pitch to get involved.
Paul Polman, CEO Unilever, said: "There is no business case for enduring poverty. The Sustainable Development Goals are a once in a lifetime opportunity to end poverty and tackle climate change."