One major symbol in The Great Gatsby is the green light at the end of Daisy's dock. Before their reunion, Nick witnesses Gatsby staring at the green light and even reaching out for, showing his longing to be with Daisy. When the finally do reunite, the green light loses its meaning for Gatsby. Fitzgerald comes back to the light at the end of the book, likening it to the "fresh green breast of the new world" that the first Dutch settlers of New York saw when they arrived. The green light represents Gatsby's dream, a beakon off in the distance.
Another symbol is the eyes of Dr. T.J. Eckleburg, which perch on a billboard for an eye doctor above the Valley of Ashes. These eyes represent the eyes of God that see the sins of the characters, at least in the mind of George Wilson as he grieves Myrtle's death and prepares to murder Gatsby and kill himself.