Usage of the school seal dates back as far as the 1920s, though the original seal's origins are unknown. The school seal has been replicated numerous times over the span of multiple decades with the technology available at the time. The detail in the seal's features had become worn, which prompted a refurbishment circa 2010.

The Joseph Sears School seal was enhanced in 2016 to further refine the original seal's features and incorporate historical significance to its details. The school seal was also produced in full color for the first time in school history. Usage of the school seal in school district publications, documents and materials has been limited in order to preserve its significance.

A The three outer rings of the school seal signify the three sequential key events that led to the establishment of The Joseph Sears School. Green represents Joseph Sears’ purchase of land on Nov. 1, 1889 to establish Kenilworth. Red represents Mrs. Mary Keyes Babcock’s School for Young Ladies and Children, the first academic institution founded in Kenilworth. Light blue represents the Rugby School for Boys, Kenilworth’s second academic institution. The standards set by these two schools laid the foundation for The Joseph Sears School.

B The school name is written in reflex blue on a white background to reference Joseph Sears school colors.

C Branches have been colored green to symbolize Kenilworth, elm trees and the Kenilworth community.

D Elm leaves, symbolic of Kenilworth, surround a book which represents The Joseph Sears School. This communicates the idea that the Kenilworth community constantly provides support to the school district.

E The book, symbolic of The Joseph Sears School, has white pages bound by a red binding. White symbolizes the school’s commitment to delivering a balanced and impartial education for all students. Red symbolizes the creativity and passion with which the faculty deliver education.