Armonk is a hamlet located in the town of North Castle in Westchester County. As of the 2010 census, Armonk had a population was 4,330.

Armonk is home to the global headquarters of information technology company IBM and bond insurer MBIA, and the Americas headquarters of reinsurer Swiss Re.

The Smith Tavern, a historical site and landmark of the Revolutionary War, is located in Armonk and is the home of the North Castle Historical Society. The North Castle Public Library, a member of the Westchester Library System, is also located in Armonk. Whippoorwill Country Club is located in Armonk and is one of Westchester's best courses.

Armonk has a total area of 6 square miles and home to over 1,172 households.

The Byram Hills Central School District serves North Castle, New Castle, Mount Pleasant, and Bedford. All of the schools in the district are located in Armonk. The district has one secondary school, Byram Hills High School (9–12), one middle school, H. C. Crittenden Middle School (6–8), and two primary schools, Wampus Elementary School (3–5) and Coman Hill Elementary School (K-2).[4] Before 2002, grade 5 was in Crittenden, grades 3 and 4 were in Coman Hill, and grades K through 2 were in Wampus.

Armonk plays host to several events that take place annually. Most notably is the Armonk Outdoor Art Show, a fine art and fine crafts juried show sponsored by Friends of the North Castle Public Library, where nearly two hundred artists working in various media gather in IBM Park to show and sell their work to patrons. The event draws a big crowd every year and involves many members of the local community as volunteers. The proceeds from this show and the Art After Dark Preview Party fund raiser held prior to the opening benefit the North Castle Public Library and its Whippoorwill Hall performance auditorium. The Friends also sponsors the Armonk Players, a community theater group that stages two full productions and several readings each year at Whippoorwill Hall to benefit the library.

The latest Armonk tradition is Frosty Day. A parade goes down Main Street, onto Bedford Avenue, past the “Village Square” mentioned in the song, "Frosty the Snowman", to Wampus Brook Park for a gala holiday lighting ceremony. After the holiday lighting, the activities continue with the Winter Walk through town.

Although Armonk is a small town, it is home to numerous shops, restaurants and salons. Some of these locations include, Access Physical Therapy & Wellness, Armonk wines & Spirits, Armonk Vision, Tazza Cafe, The Moderne Barn, Restaurant North, Gavi, Mariachi Mexican, La Mer Seafood, The Beehive, Fire Pit Tavern, Cherry Blossom Farms, North Castle Spa Nails, Salon Bellezza, Rave Revues Hair Salon, Cherylyn North Salon, Salon Elle, Changes Salon, Amore Pizzeria, Fernandoes Pizzeria, Made in Asia, Kira Sushi, Nick's Corner Market, Beascakes Bakery, Ruthie'Z clothing boutique and True Grace, The Electronics Store, LaGravinese Jewelers, Susan Blake Jewelers, and Jolie B. Ray Jewelers.