There is no definitive answer to this question as it depends on the breed of bantam chicken. Some bantam chicken breeds have been known to live for over 15 years, while others have a shorter life expectancy of around 6-8 years. The oldest bantam chicken on record was a Sebright bantam chicken which lived to be 16 years and 9 months old. However, this is not the norm and most bantam chickens will live for between 6-10 years.