There have been many statutes known as Militia Act, or, when proposed and before passage into law, the Militia Bill.
Militia Ordinance, or Militia Bill, proposed in 1642 in England
The King's Sole Right over the Militia Act 1661 (13 Cha. 2 St. 1. c. 6), England
Militia Act 1662 (14 Cha. 2. c. 3), England, defining lord-lieutenants' powers to raise militia
Militia Act 1745 (19 Geo. 2. c. 2), Kingdom of Great Britain
Militia Act 1757 (30 Geo. 2. c. 25), creating a militia to defend Britain during the Seven Years' War, leading to the creation of The Poker Club in Scotland
Militia Act 1786 (26 Geo. 3. c. 107), an act of the Parliament of Great Britain
Militia Acts of 1792 (Uniform Militia Act), two acts passed by the United States Federal government
Militia Act (Ireland) 1793 (33 Geo. 3. c. 22 (I))
Militia Act 1797, to create a uniform Scottish militia
Militia Act of 1808, United States
Militia Act of 1855, Canada
Militia Act of 1862, United States
Militia Act of 1903 (Dick Act), United States
Militia Act 1802 (42 Geo. 3. c. 90), United Kingdom
Militia Act 1803 (43 Geo. 3. c. 50), act of the Parliament of the United Kingdom
Militia Act of 1845, to create the Nelson Battalion of Militia in New Zealand
Militia Act 1882 (45 & 46 Vict. c. 49), United Kingdom, amended by the Reserve Forces and Militia Act 1898