Analysis: What's Up With the Title?
On the surface, this is a pretty easy one. The Lady of Shalott is the heroine of the poem and the heroine of the title. Tennyson focuses us right away on the importance of the Lady. For all the poem has to say about Lancelot and Camelot, this is really her story.
For extra English lit. bonus points, we'll tell you that the Lady's name comes from the legend of Elaine of Astolat, a woman who died for the love of Lancelot. Tennyson changed her name to Shalott for this poem, and created a lot of the details himself.