Logan Huntzberger is the second child of Mitchum and Shira Huntzberger (portrayed by Gregg Henry and Leann Hunley). Born in 1982 he is heir to the Huntzberger Publishing Company, a national newspaper conglomerate. He has an older sister, Honor. Traditionally a chronic ladies man and more interested in partying than studying, he first takes little note of Rory.

By the end of Season 5, they were in a monogamous relationship, which was somewhat volatile and characterized by communication issues. The couple break up and reunite multiple times, though it turns out that they have differing views on what constitutes a break up. Logan was threatened by the arrival of Jess in Season 6, even more so when he found out that Jess and Rory had been "high school sweethearts", and was patronising and aggressive towards him. After Rory argued with Logan about his behaviour towards Jess and the aimlessness of their life together, they decided to "take a break". However, Logan saw this as a break up and proceeded to sleep with his older sister's friends to make himself feel better. Logan is also known for making grand, romantic, and often ridiculously expensive romantic gestures (usually as an apology), such as purchasing a coffee cart and barista for Rory's own personal use. Initially this worked, until Rory found out that he had slept with his sister's friends just before Honor's wedding, which caused a more serious rupture. At the end of Season 6, he is sent to London by his father to take charge of his family's business and, according to Mitchum, "set him on a path." Season 7 sees him acquiring an interest and penchant for his work (in London, then in New York), and the relationship suffers.

Later, after getting involved in a bad business venture that brings a lawsuit in Season 7, Logan quits working for his father and things start to get serious between Logan and Rory. Although Rory and Logan have a fight, Logan asks Lorelai's permission to ask Rory to marry him. Logan proposes to Rory one episode later, but Rory asks for more time to think. Logan makes the offer one last time in the penultimate episode, at Rory's graduation from Yale, saying it's all or nothing. Rory still turns him down, and Logan takes the ring back, and walks off. Logan does not make an appearance in the final episode, and the series ends with them still broken up.