Guilbert and Betelle was an architecture firm formed as a partnership of Ernest F. Guilbert and James Oscar Betelle. The firm specialized in design of schools on the East Coast of the United States, with an emphasis on the "Collegiate Gothic" style.
Betelle took over the firm after Guilbert died in 1916, and oversaw design of hundreds of schools, including Greenwich High School in Greenwich, Connecticut and the Radburn School in Fair Lawn, New Jersey, both of which are listed on the National Register of Historic Places. Other notable buildings for which the firm was responsible include the Essex County Hall of Records and the Essex Club (now home of the New Jersey Historical Society).