The Arisaka rifle (Japanese: 有坂銃, romanized: Arisaka-jū) is a family of Japanese military bolt-action service rifles, which were produced and used from approximately 1897, when it replaced the Murata rifle (村田銃, Murata-jū) family, until the end of World War II in 1945. The most common models include the Type 38 chambered for the 6.5×50mmSR Type 38 cartridge, and the Type 99 chambered for the 7.7×58mm Type 99 cartridge, which is comparable in power to a modern .308 Winchester round.

The Arisaka rifle was designed under the supervision of Colonel Arisaka Nariakira (有坂 成章; 1852–1915), who was later promoted to lieutenant general and also received the title of baron from Emperor Meiji, in 1907. The design was similar to, and may have been influenced by the German Rifle Test Commission 8mm Model 1888 bolt-action rifle, which was based on the earlier Mauser design. Over the course of several wars, the rifle went through multiple production runs, during which several variants were developed, including the transition from the 6.5mm Type 38 cartridge to the larger 7.7mm Type 99, as well as the introduction of a paratrooper rifle that could be broken down into two major parts for easier storage during airborne operations. Post war testing of Arisaka rifles revealed that their bolts and receivers were constructed of carbon steel "similar to SAE steel grade No. 1085 with a carbon content of 0.80% to 0.90%, and a manganese content of 0.60% to 0.90%." During destructive stress tests, the Arisaka rifles were shown to be stronger than the American made M1903 Springfield, British made Lee–Enfield, and German Mauser rifles. The Arisaka rifles were also one of the only firearms of the era to use polygonal rifling in its barrel, rather than lands and grooves.

Some of the early issue Type 99 rifles were fitted with a folding wire monopod intended to improve accuracy in the prone position. The rear sights also featured folding horizontal extensions to give a degree of lead suitable for firing at aircraft. Near the end of World War II, ersatz models were manufactured with various cost-cutting measures, with the goal of cheaply bolstering the imperial armed forces. Some of these cost cutting measures included the replacement of the ovoid bulb-shaped bolt of earlier runs with a smaller, more utilitarian cylindrical shape. Additionally, the hand guard on the barrel was omitted, and crude fixed sights were fitted to the weapon.

The Arisaka bolt-action service rifle was used everywhere in the Imperial Japanese Army and the Imperial Japanese Navy. Prior to World War II, Arisakas were used by the Royal Navy and Russian Army, in Finland and Albania. The Czech Legions that fought in the Russian Revolution were almost entirely armed with Type 30 and 38 Arisaka rifles. Many captured rifles were employed by neighboring countries both during and after World War II, by nations such as China, Thailand and Cambodia. After the Japanese surrender from World War II in the summer of 1945, the manufacture of Arisaka rifles and ammunition stopped abruptly, quickly becoming obsolete. As most weapons from the Imperial Japanese Armory were thrown into Tokyo Harbor after the signing of the surrender, ammunition for the Arisaka rifle also became rare, although China continued to manufacture 6.5×50mmSR and 7.7×58mm for use in their captured rifles.

The imperial ownership seal, a 16-petal chrysanthemum known as the Chrysanthemum Flower Seal stamped upon the top of the receiver in all official imperial-issue rifles, has often been defaced by filing, grinding, or stamping on surviving examples. This was done by surrending Japanese forces in accordance with Military Defense Decree 1147 issued by the Japanese Ordnance Bureau in April 1914 requiring the chrysanthemum be removed for all rifles leaving imperial service. Most of the Arisakas with surviving insignia are in Japan, though there are a few remaining on samples taken as war trophies before the surrender, and those captured by Chinese forces. Some of the captured Sino Arisakas were later exported to the United States, examples including a number of Type 38 carbines and Type 44 carbines rebarrelled and rechambered for the 7.62×39mm round. Some Type 38 rifles and Type 99 rifles captured by the Kuomintang forces were also converted to fire the 7.92×57mm Mauser round.

Many of the Chrysanthemum Seals were completely ground off, although some were only defaced with a chisel, scratched off, or had the number "0" stamped repeatedly along the edges. The latter was usually done with rifles removed from Japanese military service (and thus no longer the emperor's property), including rifles given to schools or sold to other nations, such as the British Royal Navy's purchase of many Type 38s in World War I to free up SMLE rifles for their land forces.

A very small run of Type 38 rifles was also manufactured for export to Mexico in 1910, with the Mexican coat of arms instead of the imperial chrysanthemum, though few arrived before the Mexican Revolution and the bulk remained in Japan until World War I, when they were sold to Imperial Russia.

Many thousands of Type 99s and other Arisaka variants were brought to the United States by Army soldiers and Marines as war trophies during and after World War II.