Colby is part of the United Benefice of King's Beck, together with the villages of Banningham, Felmingham, Skeyton, Sloley, Suffield, Swanton Abbott and Tuttington. Sung Eucharist is held on Sunday at 10am in rotation around the churches.
The church dates from the late13th century and bears evidence of later additions and restoration. The late 15th cent. porch has some superb carvings, as does the font from the same period.
Colby appears in the Domesday Book of 1086 as Colebei (meaning "Koli's estate") and the first recorded rector was in 1314.