According to Rowling, Ron was among the characters she created on the first day. Ron is inspired by Rowling's best friend Sean Harris (to whom Harry Potter and the Chamber of Secrets is dedicated), but she has clearly stated that she "never set out to describe Sean in Ron, but Ron has a Sean-ish turn of phrase."Like Harris is to Rowling, Ron is "always there" when Harry needs him. Ron fits many of the stereotypes expected of the sidekick; he is often used as comic relief, is loyal to the hero, and lacks much of the talent Harry possesses, at least, early on, in terms of magical power. However, he proves his bravery and magical ability several times, such as by playing 'real wizard's chess' in the first book, entering into the Forbidden Forest with Harry during the second book despite his arachnophobia, producing a full-corporeal Patronus Charm in the fifth book and even, in the seventh book, getting basilisk fangs from the Chamber of Secrets by mimicking Parseltongue without understanding it.

Some of Ron's qualities serve as foils to Harry's. Whereas Harry is an orphan with more gold than he needs, Ron comes from a loving but poor family. Many of his possessions are hand-me-downs. Harry is famous but would prefer to avoid the spotlight; Ron, in comparison, is often perceived as a mere lackey and sometimes becomes jealous of the recognition Harry receives. Overshadowed by his many siblings and the fame and achievements of his friends, Ron's inferiority complex and need to prove himself are the main thrusts of his character arc. As the books progress, he matures from an insecure boy to a competent young man capable of strategy and leadership.