Gendry is a fictional character in the A Song of Ice and Fire series of epic fantasy novels by American author George R. R. Martin, and its HBO television adaptation Game of Thrones, where the character is portrayed by English actor Joe Dempsie.

First appearing in A Game of Thrones (1996), Gendry is a blacksmith apprentice in King's Landing, and an unacknowledged bastard of King Robert Baratheon. He subsequently appeared in A Clash of Kings (1998), A Storm of Swords (2000) and A Feast for Crows (2005). After Queen Cersei Lannister orders the execution of all of King Robert's bastards, Gendry is forced to flee King's Landing alongside Arya Stark under the protection of Yoren, a recruiter for the Night's Watch. He later joins the outlaw group Brotherhood Without Banners and is knighted by its leader Beric Dondarrion, and becomes a follower of the foreign religion R'hllor.

Gendry was born in King's Landing after Robert's Rebellion ended, and is one of sixteen (twenty in the television series) bastard children of King Robert Baratheon. He is 14 years old when introduced in the first book, and is portrayed as tall and very muscled, having blue eyes and thick black hair, very similar to his biological father Robert in youth. He also looks hauntingly like a younger version of Renly Baratheon, though with a squarer jaw, bushier brows and tangled hair, but resembles his biological uncle enough that for a moment Brienne of Tarth almost mistook him for the deceased Renly. Gendry is an intelligent boy despite being born into poverty, but is also stubborn, sullen, suspicious, easily confused and shy around women, and Arya Stark commented that he looks "pained" when he tries to think.

Gendry is a biological (though illegitimate) first cousin to Shireen Baratheon, the heiress of House Baratheon on Dragonstone and King Stannis' claim to the Iron Throne. Through Robert's grandmother Princess Rhaelle Targaryen, King Aegon V's youngest daughter, Gendry is actually also a second cousin (once removed) to Rhaegar, Viserys and Daenerys Targaryen.

Despite being one of the only four surviving biological children of King Robert (along with Mya Stone, Edric Storm and Bella Rivers), Gendry never knew who his father was, though he did see Robert from afar multiple times and was once nearly trampled by a drunken Robert's horse while playing near the city gate. His mother was reported to have been an alehouse worker who died when Gendry was still a young boy, and all he remembers of her was that she had blonde hair. Later on, Tobho Mott, a master armourer from Qohor working in King's Landing, was offered double the customary fee by a "lord" with concealed identity to take Gendry in as a smith apprentice, but accepted him for free after being impressed by the boy's physique. Gendry turns out to be a talented blacksmith, and likes to spend time polishing a bull head helmet that he proudly made for himself, which earned him the nickname "Bull" by fellow orphan boy Lommy Greenhands.

Gendry is not a point of view character in the novels, and his actions are witnessed and interpreted primarily through the eyes of Arya Stark, as well as some descriptions from Eddard Stark and Brienne of Tarth. He has by far the most story arc out of King Robert's children.

In his investigation about the death of Jon Arryn, Eddard Stark meets several people who had met with Arryn shortly before his death. One of them is Gendry, who was sought by both Jon Arryn and Stannis Baratheon. Eddard immediately recognizes Gendry as a bastard child of King Robert Baratheon, and tells Tobho Mott that if Gendry ever shows interest in military service, he is to be sent directly to Eddard. Gendry has shown promise as a blacksmith and made a helmet in the shape of a bull head. Eddard compliments the helmet, offering to purchase it, but Gendry refuses, to the embarrassment of his master.

After King Robert's death and Eddard Stark's political fall and eventual public execution, Varys makes arrangements for the Night's Watch recruiter Yoren to take Gendry to the Wall in order to protect him from Queen Cersei's purge. Gendry travels north with Yoren and thirty other recruits including Lommy Greenhands, Hot Pie and a disguised Arya Stark. Not far from King's Landing they are stopped by several Gold Cloaks from the City Watch, who demand that Yoren give up Gendry as he is wanted by Queen Cersei. Yoren refuses, and threatens off the Gold Cloaks with his recruits.