Daniel Randolph "Dan" Humphrey was born on April 20, 1991. Dan "Lonely Boy" Humphrey is the son of rock musician Rufus Humphrey and artist Alison Humphrey, and is the older sibling of Jenny Humphrey. Dan is a poet and used to attend the St. Jude's School for Boys with enemy Chuck Bass and previous rival for his love interest and now best friend Nate Archibald. Although accepted to Yale, he now attends NYU. He used to long for Serena van der Woodsen since a party when they were in ninth grade, and she was the only person who talked to him. He used to despise Serena's best friend, Blair Waldorf; but became best friends with her and has since dated.

Dan is clever, witty and patient; he works hard for what he wants and normally achieves his goals. Although unexperienced with plotting and manipulation, he demonstrates promise when scheming with Blair. Dan reveals at the end of the series that he was Gossip Girl from the beginning for a way for him to win Serena by writing himself into the Upper East Side, a task he succeeded in by the end of the series. In the finale, Dan and Serena get married, surrounded by friends and family.