 He married his wife Emma in 2010 and has two children, Oliver James (2013) and Esmé Amelia Rose (2015).After being spotted by Geoff Cook, Durham's coach, Onions made his second XI debut for the club at the age of 18.He was offered a contract with the club and opted to become a professional cricketer rather than take a sports science choice at university, which was his other option.