Who is the protagonist of The Great Gatsby?

Your question is a complicated one since we, the readers, only see what our narrator, Nick Carraway, relays for us. Our perception of the characters is filtered through Nick's own bias and judgement. So if we ask who the protagonist of the novel is according to Nick, we could say confidently that it is Jay Gatsby. Nick admires Gatsby for his audacity and his dreams. He knows by the end of the story...

Your question is a complicated one since we, the readers, only see what our narrator, Nick Carraway, relays for us. Our perception of the characters is filtered through Nick's own bias and judgement. So if we ask who the protagonist of the novel is according to Nick, we could say confidently that it is Jay Gatsby. Nick admires Gatsby for his audacity and his dreams. He knows by the end of the story that Gatsby is a fraud named Gatz who made his money through bootlegging and illegal gambling, but despite all that he finds himself impressed by his neighbor's relentless and exuberant determination in pursuing his dream of rekindling his five-year-old relationship with Daisy Buchanan. As Nick writes:

If personality is an unbroken series of successful gestures, then there was something gorgeous about him, some heightened sensitivity to the promises of life.… [Gatsby had] an extraordinary gift for hope, a romantic readiness such as I have never found in any other person and which it is not likely I shall ever find again.

In fact, Gatsby comes to represent, in Nick's mind, the American Dream itself. Nick writes:

Gatsby believed in the green light, the orgastic future that year by year recedes before us.… Tomorrow we will run faster, stretch out our arms farther.… 

While Nick tells the tale, so that we might think of him as the protagonist, he focuses his spotlight on Gatsby, backing most of his [Nick's] own story out, telling it, usually, in quick summaries or through suggestive, fragmented hints. Gatsby is the figure who has captured his imagination. It is for Gatsby that Nick's prose soars to lyrical levels. For Nick, and perhaps also for the reader, all the other character's pale against pink-suited Gatsby's romantic tragedy, and the collapse of his oversized dreams.