The famous poet known for his melancholic themes and association with the Romantic movement is John Keats. His poetry often explores deep emotional landscapes, beauty, and mortality, reflecting the turbulent human experiences of love and loss. Works like "Ode to a Nightingale" and "Ode on a Grecian Urn" showcase his mastery of rich imagery and lyrical expression. Keats' intense focus on sensory experiences and the fleeting nature of life resonates with the core ideals of Romanticism, making him a significant figure in literary history.