In 1651 Parliament activated the militias across England and Wales to help counter the Scots invasion led by Charles II. Several regiments fought at the Battle of Worcester alongside the New Model Army, while others were still assembling or were assigned to guard key cities. Based on Malcolm Atkin's Cromwell's Crowning Mercy The Battle of Worcester 1651 (Sutton Publishing 1998), these lists show both named regiments present at Worcester and county contingents ordered to certain rendezvous points. The named regiments have not all been assigned to specific counties yet.

• Colonel Haynes
• Colonel Matthews
• Colonel Marsh
• Lord Grey (Leicestershire Militia?)
• Cheshire Militia
  • Colonel Bradshawe
  • Colonel Brooke
  • Colonel Croxton
• Essex Militia
  • Colonel Cooke
  • Colonel Honeywood
  • Colonel Matthews
• Worcestershire Militia
• Surrey Militia (part)

• Worcestershire Horse
• Barton's Horse

• Kendrick's Dragoons
• Worcestershire Dragoons

Several of these units fought at Worcester, but 5000 militia were held in reserve at Coventry

• Leicestershire Militia (under Lord Grey at Worcester?)
• Rutland Militia
• Northamptonshire Militia (at Worcester)
• Warwickshire Militia
• Oxfordshire Militia
• Lincolnshire Militia (sent to Madresfield)
• Bedfordshire Militia
• Huntingdonshire Militia
• Worcester Militia (diverted to Gloucester then at Worcester)

• Sussex Militia
• Surrey Militia (part at Worcester)
• Hampshire Militia
• Berkshire Militia
• Norfolk Militia
• Suffolk Miltia (at Worcester)
• Essex Militia (at Worcester)
• Cambridgeshire Militia
• Twistleton's Kent Dragoons

• Gloucestershire Militia
• South Wales Militia
• Monmouthshire Militia
• Herefordshire Militia
• Wiltshire Militia

• Middlesex Militia

• London Trained Bands (15,000 under Skippon)