Ronald Bilius Weasley was born 1 March, 1980, to Arthur and Molly Weasley (née Prewett), at the height of the First Wizarding War. During this war his maternal uncles Fabian and Gideon Prewett, both members of the Order of the Phoenix, were murdered while fighting a group of four Death Eaters led by Antonin Dolohov. While he was still a toddler, the war ended for a time after Lord Voldemort's first defeat at the hands of Ron's classmate-to-be Harry Potter on 31 October, 1981. 

Ron and his five older brothers — Bill, Charlie, Percy, Fred and George — as well as his younger sister, Ginny, grew up in The Burrow on the outskirts of Ottery St Catchpole in Devon, England. Like all his siblings, he was home educated in reading, writing and simple mathematics by his mother. The Weasley family was not wealthy at all, compared to other wizarding families. Many other pure-blood families, particularly the Malfoys, disdained them for their "blood traitor" beliefs and lack of wealth. They tried their best to make up for this with their love.

The Weasley siblings, especially Fred and George, were fond of teasing and playing pranks on each other, and Ron was a particular target for Fred and George. They once transfigured Ron's teddy bear into a giant spider, sparking his arachnophobia. On another occasion, the twins nearly got him to make an Unbreakable Vow, which finally made their father truly furious (and Fred would later state that his left buttock has "never been the same since" after the row that ensued). They also once got him to eat an Acid Pop which burnt a hole through his tongue.

When Ron was younger, he had a pet rat named Scabbers, whom he had inherited from Percy. This rat was actually Peter Pettigrew, a traitor to all wizardkind. Ron was very fond of Scabbers, but wasn't sad to let him go when he found out the truth about his old rat. Ron had a fairly happy childhood, which Harry, who had been brought up by his spiteful relatives the Dursleys, envied. To compensate for their impoverishment, Ron's mother indulged him in three delicious meals daily. This became so habitual that missing a meal in later life would irritate Ron.

Ron inherited the typical Weasley family traits: fiery red hair and a freckled complexion. When he became embarrassed, his ears notably turned red. He had blue eyes, a long nose, and was described as being very tall and lanky, with big hands and feet. In this way, his stature was similar to those of his older brothers Bill and Percy, rather than the heavily built Charlie, and Fred and George.

His sister Ginny once joked to the trio that Ron had a Pygmy Puff tattoo, though it is doubtful that the remark had any truth in it.

By 2014, when he was at the age of 34, Rita Skeeter remarked on a Daily Prophet gossip column that his "famous ginger hair appears to be thinning slightly".

By 2017, Ron had settled into a round middle age and was later described to be getting "a bit of a gut" by his nephew, yet hiding it extremely well.

He had scars from the brains which attacked him in the Thought Room in the Battle of the Department of Mysteries.

Physical Appearance 

Ron was a very loyal, brave, strong and humourous person, but sometimes immature, and insensitive. He had a sardonic, wisecracking sense of humour that often brought his friends laughter and relaxation. However, as Hermione Granger and Luna Lovegood pointed out, his humour could occasionally be hurtful, even if unintentionally. During his time searching for Voldemort's Horcruxes with Harry and Hermione, Ron matured greatly, and even took to leading the trio when Harry temporarily fell into a depressive mood.

Though his loyalty and bravery never faltered Ron's character was also marked by occasional jealousy and insecurity rising from feeling overshadowed by his five older brothers and his parents' constant comparisons between him and their other children. He could be argumentative, a trait particularly displayed in his bickering with the equally argumentative and occasionally highly critical Hermione. Though their bickering was frequent, it was never malicious (with the brief exception of sixth year) and generally a way to hide their deeper feelings for each other. Inheriting the Weasley trait of a strong temper Ron was not above provocation especially when dealing with the spiteful treatment of Professor Snape and the bigotry and hatred of Draco Malfoy. Always willing to stand up for his friends and family even when angry with them, Ron never stopped standing up for Hermione when she faced Muggle-born related prejudice and hatred. He also stood by Harry's side when he was met with disbelief and scorn from his classmates and Wizard society in general. Ron frequently demonstrated great bravery in attempting to protect those he loved, from facing his arachnophobia to stand by Harry in his second year to trying to take Hermione's place when Bellatrix Lestrange isolated her for interrogation with the Cruciatus Curse.

As a boy, Ron was very sensitive about his family's poverty, and sometimes embarrassed by them. Many, if not all, of Ron's possessions were hand-me-downs, including his robes, school books, wand, and even a pet rat whom he called Scabbers. His family's lack of finances often made Ron a target for taunting by Draco Malfoy, a spoiled, arrogant Slytherin. Ron was also prone to insecurity about his abilities, when compared to his older siblings and to his famous best friend. When he felt insecure or embarrassed, it was noted that his ears turned red. This became his tell-tale sign of his anger and embarrassment. He felt as if he was consistently overshadowed by the legacy of his older brothers and the fame of Harry; this lead to a feeling of being "second-best". Although passionate about Quidditch, especially the Chudley Cannons, and a fine flyer, Ron had a problem with nerves, and sometimes his playing ability suffered for it. Salazar Slytherin's Locket revealed that Ron's deepest fears were that his mother loved him least and that Hermione preferred Harry to him. He also suffered from arachnophobia, a fear originating from his brother Fred transfiguring his teddy bear into a spider when Ron was a child.