John Grigg may refer to:

• John Grigg (astronomer) (1838–1920), New Zealand astronomer
• John Grigg (politician) (1828–1901), New Zealand politician
• John Grigg, 2nd Baron Altrincham (1924–2001), British writer and disclaimed peer

• Ken Coogan
• Ken Cooley
• Ken Cooper
• Ken Cooper (American football coach)
• Ken Cooper (American football guard)
• Ken Cooper (disambiguation)
• Ken Corbet
• Ken Corley
• Ken Cormier
• Ken Cosgrove
• Ken Costa
• Ken Crawford
• Ken Crawford (American football)
• Ken Crawford (astrophotographer)
• Ken Crawford (baseball)
• Ken Crawford (disambiguation)
• Ken Crawford (football)
• Ken Cumberland
• Ken Cunningham (disambiguation)
• Kenda-5 Hour Energy
• Kendab
• Kendah Sar
• Kendaia
• Kendal band
• Kendal castle