Nearly three-quarters of Monmouthshire residents do not have a library within a 15 minute walk, new figures show.
A charity for public libraries has called for improved funding for local councils to help provide for their communities.
Analysis from the Office for National Statistics shows 28% of Monmouthshire residents had a library within a 15-minute walk of their home.
Meanwhile, 56% were within half an hour of a library, and 77% of residents could reach one within an hour's walk.
The ONS' figures show Monmouthshire had six open libraries as of August, or one for every 15,800 people in the area.
Across England and Wales, people in rural areas less often had a library within 15 minutes of them, although those living in some towns are also missing out.
Londoners are far more likely to have a nearby library than other regions – nine out of the top 10 areas were in the capital. By comparison, half of the bottom 10 were in the West Midlands, while four were in the South East.
James Gray, communications and advocacy manager at Libraries Connected, said everybody should have access to high quality local library services.
"Whether in cities, towns or rural areas, libraries play an essential community role: providing free access to books and information, developing digital skills, supporting business, encouraging healthy lifestyles and much more," he added.
"Library services will naturally vary across the country, but this must reflect the needs of their local communities, not the need to make savings."
Mr Gray urged ministers to fix local government finances so that councils can properly resource and staff libraries in their areas.
The Arts Council said access to creativity and culture can improve wellbeing, but warned creative opportunities are "denied to too many in this country".
A recent investigation by the BBC found more than 180 council-run libraries have either closed or been handed to volunteer groups since 2018, and 2,000 jobs lost.
Councillor Liz Green, chair of the Local Government Association's culture, tourism and sport board, said councils are the "biggest public funder of culture", which includes maintaining 3,000 libraries.
"Libraries are multi-use spaces providing educational and leisure resources as well as acting as trusted community hubs and locations for vital community services such as employment and health care support," she added.
"Recent LGA research shows that councils in England are facing a £2.3 billion funding gap in 2025-26, rising to £3.9 billion in 2026-27. This means that many councils are facing the difficult decision to close libraries down in order to maintain funding for statutory services."
The LGA is calling on the Government to provide a "significant and sustained" increase in funding to help provide community services.