The regiment was formed in 1964 during the reorganisation of the army by the amalgamation of two separate regiments; the Canterbury Regiment and the Nelson, Marlborough, West Regiment.

In turn, these two regiments had originally been formed from the 1st (Canterbury) and 2nd (South Canterbury) and the 12th (Nelson and Marlbourgh) and the 13th (North Canterbury and Westland) regiments, which had been initially raised in the early 1900s, following the formation of gazetted militia units in 1859.

In 1964 amalgamation saw the new Territorial Force battalion become the Second Battalion of the Royal New Zealand Infantry Regiment. This was until the later reorganisation of 1999, which saw the Territorial Force battalion split from the RNZIR to become multi-function battalion groups.

The 2nd Battalion (Canterbury, and Nelson-Marlborough and West Coast) RNZIR became the 2nd Canterbury (Nelson, Marlborough, West Coast) Battalion Group, with the following sub-unit types:

• Infantry – North Canterbury Company, South Canterbury Company, Nelson Company, Marlborough Company, West Coast Company
• Artillery – 32 (Observation Post) Battery, RNZA
• Engineers – Support Company Medical
• Single – Support Company
• Logistics – Logistic Company
• Brass Band

In December 2012, 2nd Canterbury (Nelson, Marlborough, West Coast) Battalion Group merged with 4th Otago and Southland Battalion Group to form 2/4 Battalion