Maggie's centres are a network of drop-in centres across the United Kingdom and Hong Kong, which aim to help anyone who has been affected by cancer. They are not intended as a replacement for conventional cancer therapy, but as a caring environment that can provide support, information and practical advice. They are located near, but are detached from, existing NHS hospitals.

The Scottish registered charity (registration number SC024414) which promotes, builds and runs the centres is formally named the Maggie Keswick Jencks Cancer Caring Trust, but refers to itself simply as Maggie's. It was founded by and named after the late Maggie Keswick Jencks, who died of cancer in 1995. Like her husband, architectural writer and critic Charles Jencks, she believed in the ability of buildings to uplift people. The buildings that house the centres have been designed by leading architects, including Frank Gehry, Zaha Hadid and Richard Rogers.

Patrons of the charity include Frank Gehry, Jon Snow, Kirsty Wark, and Sarah Brown, wife of former British prime minister Gordon Brown. The charity's chief executive officer is Laura Lee, who was Maggie's cancer nurse. The President of the charity is Camilla, Duchess of Cornwall.