Fire-Making Spell

"From everyday uses such as fire-lighting, to igniting the occasional Christmas pudding the Fire-Making Spell is one of the most useful spells around the wizarding household."

- Entry on this spell in Book of Spells.

The Fire-Making Spell (Incendio) is the incantation of a spell that set things alight.

Known uses
""Incendio!" said Mr Weasley, pointing his wand at the hole in the wall behind him. Flames rose at once in the fireplace, crackling merrily as though they had been burning for hours."

- Arthur Weasley uses this spell at the Dursleys' house in 1994.

Known practitioners

 * Orabella Nuttley
 * Albus Dumbledore (possibly)
 * Arthur Weasley
 * Bellatrix Lestrange (possibly)
 * Colin Creevey
 * Filius Flitwick (possibly)
 * Fred Weasley
 * George Weasley
 * Harry Potter
 * Hermione Granger
 * Neville Longbottom
 * Pomona Sprout
 * Remus Lupin (possibly)
 * Ron Weasley
 * Rubeus Hagrid (possibly)
 * Thorfinn Rowle

Etymology

 * In Latin, incendio is the dative or ablative singular of incendium, "fire", and can mean "to fire" or "for fire" (dative), "by fire" or "with fire" (ablative of instrument or means). Thus, the incantation is a way of calling upon fire to burn a desired object, since the spell caster wills harm to be done to an object "by (means of) fire."
 * "Incendio" is the Catalan and Portuguese word for "fire".
 * "Incendio" (pronounced in-cen-DI-u) is also the first person singular of the present of the Spanish verb "incendiar", meaning "to set fire to".

Behind the scenes
This may be the spell Remus Lupin used on the Hogwarts Express 1993, combined with a Flame-Freezing Charm when the lights went out as he is described as "holding a handful of flames" though it is more likely that he used the charm for Bluebell flames. This may also be the spell he used to relight candles during the Patronus lesson.
 * In the video game adaptations of Philosopher's Stone and Chamber of Secrets, Incendio is the Bluebell flames charm Hermione uses in the first book. It is used primarily to wilt dank-loving, threatening plants and burn through spider webs. In the later games it resumes its use as a spell to conjure a small burst of normal fire.
 * When Rowle used the spell offensively against Hagrid's hut, it caused an explosion, rather than simply lighting it on fire.
 * Incendio is the first known spell to be cast in the series, although magical devices (Albus's Put-Outer), abilities (Animagi) and beings (Hagrid) appeared before.
 * In the sixth film, Bellatrix uses this spell to set Hagrid's hut on fire instead of Rowle.
 * According to Pottermore, the hand movement is shown as thus:

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Philosopher's Stone (video game)
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Goblet of Fire (video game)
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film) 
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows: Part 1
 * Harry Potter and the Deathly Hallows: Part 2
 * LEGO Harry Potter: Years 1-4
 * Harry Potter: Spells
 * Pottermore
 * Harry Potter Trading Card Game
 * Wonderbook: Book of Spells
 * Harry Potter for Kinect

Notes and references
Hechizo para Producir Fuego Sortilège de Feu אינסנדיו Incantesimo del Fuoco Sytyjo