Even before firearms were available, there have been soldiers, such as archers, specially trained as elite marksmen.

The first modern firearm snipers may have been trained in 16th century Japan as a type of ninja or shinobi. They were supposedly trained to cover retreating armies. The sniper would lay in concealed ambush until an officer of the advancing army came into his firing range. There are several confirmed records of such attempts. Most were unsuccessful; the rifles used were of large caliber, but poor accuracy. Despite this, one of Japan's most famous warlords, Takeda Shingen, is reported to have been fatally wounded by a sniper's bullet.

France's Louis XIV trained elite riflemen to shoot armored knights. Their guns weighed more than 9 kg (20 lb), and were capable of shooting 30 g (1 oz) lead balls fast enough to put a bullet through plate armor. Some authorities claim that they, alone, made heavy cavalry (knights) obsolete.

Timothy Murphy was a rifleman in Daniel Morgan's Virginia riflemen in 1777. He shot and killed General Simon Fraser of the British army. Murphy was said to have taken the shot at roughly 450 m (500 yd), astounding at the time. He was using the renowned Kentucky rifle. The death of General Fraser caused the British advance to falter and the rebels to win the battle.

During the pivotal Battle of Trafalgar, on October 21, 1805, as the British flagship HMS Victory locked masts with the French Redoutable, a sharpshooter's bullet struck Admiral Horatio Nelson in the spine. Nelson was carried below decks and died as the battle that would make him a legend was ending in favour of the British. Sharpshooters were sometimes employed during boarding actions and at close range, their positions in the fighting tops allowing them to shoot enemy officers, whose gaudy uniforms made them extremely visible. This visibility was offset by the poor accuracy of the firearms, poor training and ship sway.

In the Napoleonic Wars, the British copied colonial weapons and tactics in a limited number of rifle companies. They dressed (unsportingly) in green to avoid visibility, and were instructed to shoot enemy officers.

Rifleman Thomas Plunkett of the 1st Battalion, 95th Rifles is remembered for shooting General Colbert at a range of between 200 and 600 metres during the Peninsula war. He used a Baker rifle.

Colonel Hiram Berdan was the commanding officer of the 1st and 2nd US Sharpshooters. Although snipers were held in low regard by both sides during the American Civil War, under his tutelage, skilled Union marksmen were trained and equipped with the .52 caliber Sharps Rifle. It has been claimed that Berdan's units were responsible for killing more enemies than any other unit in the Union Army.

On May 9, 1864 during the Battle of Spotsylvania Court House, Sgt. Grace of the 4th Georgia Infantry, sniped Major General John Sedgwick at the then incredible distance of 730 m (800 yd), with a British Whiteworth target rifle. The death of Sedgwick, a corps commander, caused administrative delays in the Union's attack, leading to Confederate victory. Before Sedgwick was shot, he was advised by his men to take cover. Legend has it that his last words were, "They couldn't hit an elephant at this distance," upon which he was shot. In reality, he was shot a few minutes later.

Simo Häyhä (December 17, 1906 – April 1, 2002) of Finland is regarded by many as the most effective sniper in the history of warfare. Using a relatively primitive Mosin-Nagant Model 28, Häyhä sniped 542 Soviet Union soldiers in the Winter War between November 30, 1939 and March 6, 1940, when he was seriously wounded. Sulo Kolkka was also a Finnish sniper during the Winter War who sniped approximately 400 Russians, as well as killing another 200 with a submachinegun. Owing in part to the superb quality of Finnish snipers, the Russians lost men at a rate of 40:1. At the end of the Winter War a Soviet general is said to have bitterly remarked, "We gained 57,000 km² (22,000 square miles) of territory. Just enough to bury our dead."

Vasily Zaitsev was a Russian sniper who burst into fame during the Battle of Stalingrad, credited with sniping 242 German soldiers. He became a folk hero for his bravery at Stalingrad and for killing the German master sniper instructor Major Thorvald, in an extended sniper-countersniper duel. However, there are debates as to whether Thorvald actually existed, or was the invention of Soviet propaganda writers. Zaitsev was the main subject in the movie Enemy at the Gates, a fictionalized account of sniper-warfare in the Battle of Stalingrad.

Lyudmila Pavlichenko was a female Ukrainian sniper with 309 confirmed kills during World War II.

Gunnery Sergeant Carlos Hathcock of the United States Marine Corps sniped 93 North Vietnamese soldiers during the Vietnam war. He is the subject of two biographies, Marine Sniper and Silent Warrior.

Delta Force snipers Gary Gordon and Randy Shughart were both killed in action during the Battle of Mogadishu. It is estimated that together they shot over 100 Somalis. Both men received the Medal of Honor, posthumously, for their actions.

The longest-ever recorded and confirmed sniper kill was made by Master Cpl. Arron Perry of the Canadian Armed Forces in Afghanistan during combat in 2003. Using a .50-caliber (12.7 mm) MacMillan TAC-50 rifle, Perry shot and killed an Afghan soldier from a distance of 2,430 metres.