A senior house officer (SHO) is a non-consultant hospital doctor in the Republic of Ireland and many Commonwealth countries. SHOs usually have a minimum of 1 year post medical school training. SHOs are supervised in their work by consultants and registrars. In training posts these registrars and consultants oversee training and are usually their designated clinical supervisors.
The same structure to junior doctor grades also applied previously in the National Health Service in the UK, and informal use of the term persists there.