An Army Training Regiment (ATR) is a unit of the British Army which conducts basic training for all new recruits, less those of the Infantry who are trained at the ITC (Infantry Training Centre) at Catterick North Yorkshire, and some non-infantry TA units (see below).

All new recruits, whether Regular or Territorial Army, are required to pass the lichfield/training/cms_r_.htm" target="_blank">Common Military Syllabus (Recruits) (CMS(R)), commonly known as Phase 1. For regular recruits this is 14 weeks , for TA recruits this initial training is carried out over weekends at a Regional training centre followed by 2 weeks at an ATR. Not all TA recruits are trained at an ATR; for example, recruits for TA units of the _Royal Military Police complete their CMS(R) at Worthy Down, near Winchester and recruits to UKSF(R) and the Honourable Artillery Company complete CMS(R) with their own units.