453 JACKSON Millbrook 19C        
  010 JACOB Falmouth 18-19C  
  388 JACOBS St. Ives 1800-1900  
  661 JACOBS St. Teath Any  
  092 JAMES St. Just c1841    
  092 JAMES Boscaswell c1841    
  321 JAMES (Thomas) St. Hilary 1840-1875    
  071 JANE Lanhydrock c1700s    
  367 JEFFERY Gwennap 17-19C    
  367 JEFFERY Cumberland 19-20C    
  424 JEFFREY St. Agnes 1750-1850    
  677 JEFFREY St. Columb Minor 1760-1800  
  303 JENKIN St. Columb Major 1800-1900  
  445 JENKIN Gerrans All  
  445 JENKIN Gorran All  
  445 JENKIN Kenwyn All  
  445 JENKIN Perranzabuloe pre1800  
  445 JENKIN St. Clement pre1825  
  726 JENKINS St. Day 1800-1860  
  195 JEWEL(L) St. Kew pre1725  
  239 JEWELL Launcells c1700s  
  636 JILLETT Somerset All  
  205 JOHN Altarnun 1600+  
  028 JOHNS St. Columb Major c1700s  
  378 JOHNS St. Mewan 1700-1800s  
  666 JOHNS Veryan 18-19C  
  205 JOHNSTONE Fifeshire, Scotland 1700+  
  205 JOHNSTOUN/ONE Edinburgh 1600+  
  303 JOSE St. Stephen in Brannel 1600-1700  
  010 JOSEPH Falmouth / Penzance 18-19C  
  303 JUBY Welbourne, Norfolk 1750-1850  
  666 JULYAN St. Columb Minor 18C