About Cos Cob Library

The Cos Cob Library is the hub of the local community. Choose from among 40,000 materials including books, movies, magazines, and CDs.

Wifi is available throughout and 12 public computers are available in the building. The Community Room displays art work throughout most of the year and the room is available for local meetings and programs. The Friends of Cos Cob Library support programs including several book clubs, numerous storytime and craft programs for children, author visits, informative lectures for adults, and much more.

It has often been stated that our library resembles ‘Cheers,’ where everybody knows your name. Visit and see for yourself!

Hours & Directions


Mon | 12 pm – 8 pm
Tues – Sat | 9 am – 5 pm
Sun | Closed


Phone: (203) 622-6883
Email Us


5 Sinawoy Road
Greenwich, CT 06807

Print at Cos Cob

Questions? Check out instructions here.


The Friends of Cos Cob Library

The Friends of the Cos Cob Library is a volunteer organization dedicated to encouraging and assisting the work of the Cos Cob Branch of the Greenwich Library by providing information to the community, sponsoring programs, and coordinating volunteer activities. In addition, the Friends of Cos Cob Library are leading the Cos Cob Library Light the Way Campaign. Support the Project here.

Learn More Button Arrow

Renovation Project

For several years, Greenwich Library has explored renovating the Cos Cob branch. The building first opened in 1999. Click through to find out more about potential improvements or to support the project.

Support the Cos Cob Library Light the Way Campaign

Project Planning Fact Sheet

Survey Summary Report

Project Announcement Fact Sheet

Project Renderings


Library History

Discover the history of the Cos Cob Library and see how far the Library has come.

Learn the History Button Arrow

Ongoing Programs

Cos Cob is excited to offer both book groups and other programs on an ongoing basis.



View beautiful photos of the Library and Library programs.

View Photos Button Arrow