Svend Åge Madsen (Danish pronunciation: [ˈsvɛnˀ ˈɔːʊ ˈmæsn̩] born 2 November 1939) is a Danish novelist. He studied mathematics before he began writing fiction. His novels are generally philosophical and humorous. Several of his works have been made into films in Denmark. His writings are extensive and has been translated into many languages.

Madsen's writing style and philosophy have placed him amongst the most distinguished and widely read authors in Denmark today. His novels reflect the grave problems faced by modern civilisation, and a number of them have achieved cult status in Denmark. The interplay between quasi-realism and complete fantasy in Svend Åge Madsen’s novels leads to contemplation of the indefinable nature of human existence.