Manga adaptation of the scenario that Type-Moon co-founders Kinoko Nasu and Takashi Takeuchi, created for the Nintendo Wii visual novel 428: Fūsasareta Shibuya de.

When Lord El-Melloi II, the later Waver Velvet, gets asked to claim his inheritance over Adra Castle, he travels there with his apprentice Gray to do so. But they are not the only ones called that way. The will of the previous owner states that the assembled contestants—including Luviagelita Edelfelt—must compete in a game of wits to win the castle.

The story follows Tohno Shiki, a teenage boy who, after a near-fatal accident in his childhood, gained the mysterious power to perceive lines covering everything around him. When he cuts along these lines, whatever it was immediately falls apart with a clean cut; in other words, killing it. He would have quickly gone insane from living in a world that could fall apart so easily, had it not been for a wandering self-proclaimed magician who gave him a pair of glasses that blocked his unnatural perception when worn.

Soon afterwards, he was disinherited from his family and sent to live with some relatives. For eight years he lived a normal life, hiding his special eyes, until one day he receives a letter inviting him to come back home. Shiki suddenly becomes caught up in strange and life-threatening series of events, ones that are somehow linked to his childhood accident and a forgotten past...

To repair the singularity of the future, the main character, Ryuka Fujimaru, will shift again to lay down a tremendous battle. Kengoro Nishide of "Umehara FIGHTING GAMERS!" Breathes new life into "FGO"

A manga which helps you learn about Fate/Grand Order!(Source: MangaDex)

A remake of the comedy spin-off manga Koha-Ace GO: Teito Seihai Kitan.

Original 4-koma updated daily

The story takes place in an ordinary Japanese town, Fuyuki City. Hidden from society, there has been a deadly war going on in this town. Seven sorcerers known as "Masters" summon a powerful familiar called "Servants" and they all fight each other till the last one. The last one is said to attain the Holy Grail which will grant them a wish. Only a few knows when this War started and what the Holy Grail is, but the war was about to begin again this year.
The main character is Emiya Shirou, who lost his parents in a fire and was adopted by a man who called himself a sorcerer. Admiring his step father, he has been training himself to be a sorcerer. However, he had no talent and he could barely use one type of sorcery. His step father has already passed away, and today he's a sorcerer without any skills or knowledge. He is involved in the War of the Holy Grail when he accidentally summons Saber, who is said to be the strongest servant of all...
(Source: MU)

The original Fate/Type Redline. Yes. The serious Fate/Type Redline originated from a comedy Koha-Ace manga. Follow the adventures of Kohaku and Akiha (characters from Tsukihime) as they fight in the Imperial Capital Grail War with Okita Souji!

A TYPE-MOON staff member artist Takenashi Eri has created many side stories to most of the group's projects; 'Tsukihime' & 'Kagetsu Tohya', 'MELTY BLOOD', 'Fate/stay night' -- you'll find your favorite characters in various hilarious situations that weren't covered by any of the original products.
from Baka-Upates Manga

The plot of Fate/hollow ataraxia is based half a year after the events of Fate/stay night. Like its preceding counterpart, the story is set in Fuyuki City. Bazett Fraga McRemitz, a member of the Mages' Association and a master in the 5th Holy Grail War, wakes on the fourth day of the 5th Holy Grail war with a new servant, Avenger, and no memory of what happened to her beforehand. She and Avenger set off to fight and win the Holy Grail War.
Meanwhile, Shirō Emiya lives a peaceful life with all his friends from the 5th Holy Grail War. After one of her experiments changes time and space, Rin Tōsaka leaves for the Mages' Association in England to fix things. The Servants sense a new danger while dark creatures appear soon afterward. Shirō, as a precaution, sets off to ensure nobody is in danger and instead finds himself frequently meeting a mysterious girl, Caren Ortensia.
Both Bazett and Shirō find themselves in time loop that lasts four days, beginning of the fourth day of the 5th Holy Grail War. Each time they die or survive four days, they always awake on the first day of the loop aware of what has happened to them since the first time loop began. Determined to end the loop, Bazett, Avenger, and Shirō fight to discover the truth behind what's causing the endless four days.
(Source: Wikipedia)

A Fate/stay Night spin-off focused on cooking.

A crossover manga of Fate/Stay Night and Magical Girl Lyrical Nanoha A's.

The story takes place in an ordinary Japanese town, Fuyuki City. Hidden from society, there has been a deadly war going on in this town. Seven sorcerers known as "Masters" summon powerful familiars called "Servants," and they all fight each other till the last one. The last one is said to attain the Holy Grail, which will grant them a wish. Only a few know when this War started and what the Holy Grail is, but the war is about to begin again this year.

The main character is Emiya Shirou, who lost his parents in a fire and was adopted by a man who called himself a sorcerer. Admiring his stepfather, he has been training himself to be a sorcerer. However, he had no talent and he could barely use even one type of sorcery. His stepfather has already passed away, and today he's a sorcerer without any skills or knowledge. He is involved in the War of the Holy Grail when he accidentally summons Saber, who is said to be the strongest servant of all...

Heaven's Feel is one of the routes in Fate/stay night. The heroine of this route is Sakura Matou.

Fate/Grand Order tie-in webcomic

Hana no Miyako is a Tsukihime and Melty Blood spin-off about Shiki Tohno's cousin, Miyako Arima.

Melty Blood: Rojiura Nightmare is a spin-off and sequel to the Melty Blood fighting games and manga, as well as the Fate/Grand Order mobile game.

The manga is an anthology story centering on the Crypters, the betrayer agents of Chaldea that are the center of the Fate/Grand Order smartphone game's "Lostbelt" story line.