Kyger studied at the University of California, Santa Barbara, before moving to San Francisco, in 1957, and becoming involved with the poetry scene around Jack Spicer and Robert Duncan.

In 1960 she joined Gary Snyder (whom she had met in San Francisco in 1958) in Japan. They were married on February 28, immediately after her arrival. She later travelled to India with Snyder, Allen Ginsberg and Peter Orlovsky. She returned to the United States in 1964 and her first book, The Tapestry and the Web was published the next year.

In 1965, she married Jack Boyce. They separated in the early seventies.

Kyger has published more than twenty books of poetry and prose, including Going On: Selected Poems, 1958—1980, (1983); and, Just Space: poems, 1979-1989 (1991). She has lived in Bolinas since 1968, where she has edited the local newspaper. She has also done some occasional teaching at the Jack Kerouac School of Disembodied Poetics of the Naropa Institute, in Boulder, Colorado.

In 2000, her 1981 collection of autobiographical writings was republished as Strange Big Moon: Japan and India Journals, 1960-1964, which Anne Waldman has called "one of the finest books ever in the genre of 'journal writing'".

More recent poetry collections include God Never Dies (Blue Press), The Distressed Look (Coyote Books), Again (La Alameda Press), and As Ever: Selected Poems published by Penguin Books.

Her most recent book is About Now: Collected Poems from National Poetry Foundation. It won the 2008 PEN Oakland Josephine Miles National Literary Award for Poetry.

In 2006 she was awarded a grant from the Foundation for Contemporary Arts Grants to Artists Award.