Which Harry Potter novel did J.K. Rowling finish writing first?

J.K. Rowling first finished writing Harry Potter and the Philosopher’s Stone. It was the opening novel of the series and established the characters, school, mythology, and conflict that the later books expanded.

Rowling developed the idea of Harry Potter during the early 1990s and worked on the manuscript while facing major personal and financial difficulties. After completing it, she found a literary agent, and Bloomsbury acquired the book. It was published in Britain in 1997, launching the series.

The wording “finished writing first” refers to the order in which Rowling completed the manuscripts, not the order in which every related story was conceived. The subsequent novels were written and published later. The book is titled Harry Potter and the Sorcerer’s Stone in the United States, but the British title, Philosopher’s Stone, is the original title and the one used by the source article.