Children as young as 10 and an 87-year-old pensioner have been tasered by police amid a sharp rise in officers firing the devices in the last three years.
A Sky News investigation has revealed details of incidents where officers have fired the 50,000-volt stun guns at minors and elderly people between 2018 and June this year.
The findings come amid calls for the UK to ban the use of Tasers on under-18s.
Police chiefs have defended using the weapons on youths, saying they commit "a lot of violent crime".
It comes after PC Benjamin Monk was convicted of the manslaughter of 48-year-old former footballer Dalian Atkinson who died after being tasered for more than six times longer than the normal cycle.
Following freedom of information requests by Sky News:
• Gloucestershire Police said a 10-year-old boy was tasered after he approached officers with a large knife and refused to drop the weapon following an incident where he threatened to harm someone.
• Bedfordshire Police tasered a 12-year-old who showed "active resistance" following a stop and search after being suspected of carrying a weapon.
• Hertfordshire Police said an 87-year-old was tasered after an officer was threatened with a firearm.
• Devon and Cornwall Police tasered a 15-year-old who was making "violent threats towards an officer" and threw a bottle which narrowly missed.
• Humberside Police said an 83-year-old man was tasered after he barricaded himself in a kitchen armed with weapons, including a knife and a large metal instrument, and was throwing items at officers.
• West Yorkshire Police tasered a 79-year-old man armed with a knife after he had harmed himself and was threatening to take his own life.
The same force also tasered a 14-year-old boy after a masked gang broke into a property and he became violent when he was found inside.
• Wiltshire Police tasered a 60-year-old with martial arts skills who had kicked and punched police officers, resulting in one officer suffering a punctured lung.
The same force also tasered a 15-year-old who assaulted an emergency worker on duty by punching him in the face and shoving him.
• South Yorkshire Police, which tasered people aged between 17 and 71, said the device was used on one person armed with a knife who was "demonstrating aggression to NHS staff".
The Metropolitan Police has previously revealed it tasered a 10-year-old girl in January following reports she was threatening a woman with garden shears and a hammer.
However the force refused to reveal the ages of the youngest and oldest people it had tasered, arguing it "could identify individuals".
In April, Scotland Yard released footage of 63-year-old Anthony Browne being tasered after he attacked a policeman with a four-foot-long sword, severing the officer's finger. Browne was later jailed for more than seven years.
West Mercia Police, which employed PC Monk when he killed ex-Aston Villa star Atkinson, said it had tasered a 63-year-old due to "concern for welfare".
Police forces also revealed they had tasered 24 dogs since 2018 including Staffordshire bull terriers, a rottweiler, an American bulldog, a husky, a German Shepherd-type breed and a Pitbull-type.
The actual number is likely to be much higher as only just over half of forces provided full information on their use of Tasers.
Sophie Khan, a solicitor who specialises in cases involving Taser-related injuries, said the use of the weapons on children and elderly people was "disturbing".
She told Sky News: "The use of less-lethal weaponry is a last resort and should not be used on children and on the elderly, who by their nature are vulnerable.
"The police forces need to recognise that Tasers are not the answer to each and every police interaction."
The number of incidents where police officers discharged Tasers in England and Wales rose by nearly a quarter last year.
Home Office data shows there were 3,300 incidents recorded in 2019/20 - up 22% on the previous year (2,700 incidents) and 65% higher than 2017/18 (2,000 incidents).
Unicef has called for the UK government to ban the use of Tasers on under-18s, saying it is "concerned" that the weapons are increasingly being used by police on youngsters.
The charity says the continued use of Tasers on under-18s runs in opposition to international children's rights standards.
In response, the Police Federation of England and Wales said officers had to "police in the real world" and "the harsh reality is some 'children' are dangerous individuals".
Louise King, director of the Children's Rights Alliance for England (CRAE), told Sky News that Tasers "inflict intolerable pain" and the government's own advisers have warned youngsters are at greater risk of injury from the devices.
"Even when they are not actually fired, children have told us how frightening it is to even be threatened with a Taser," she said.
"It is therefore extremely concerning that Taser use on children is increasing, including on very young children."
Ms King said CRAE wants the use of Tasers on children "to be eliminated" and believes officers should focus on "de-escalation and using effective communication skills" rather than firing the devices at young people.
"The police say Tasers can help them to protect the public and police officers, but that shouldn't come at the cost of children's safety and human rights," she added.
Following PC Monk's conviction for the manslaughter of Atkinson, Amnesty International UK warned there had been "enormous mission creep with Taser use in this country".
Oliver Feeley-Sprague, the organisation's policing expert, said the devices were "potentially lethal weapons" linked to a "growing number" of deaths in Britain.
"We urgently need a full review of police use of these dangerous devices and confirmation that Tasers will remain specialist weapons, limited for use in specific genuinely dangerous situations," he added.
The National Police Chiefs' Council (NPCC) has said there is "no lower or upper limit on the age" of a person who can be tasered but officers are taught that children may have an increased risk of cardiac arrhythmia - or abnormal heart rhythm.
"A child is classed as someone under the age of 18, but a lot of violent crime is carried out by people who meet the criterion of being 'under 18'", it said.
Chief Constable Lucy D'Orsi, the NPCC's lead for less lethal weapons, told Sky News: "The mere presence of a Taser is enough to bring 86% of violent or potentially violent incidents to a swift and safe conclusion without the need to fire the device.
"Every time an officer fires the device, they will need to justify their decision making.
"The accountability of Taser use is important to chief constables who have undertaken a commitment for every officer who patrols with a Taser to be equipped with body worn video."