The person speaking at the end of the poem, "The Lady of Shalott," is none other than the Lady of Shalottt herself.
<em>'They cross'd themselves, their stars they blest, </em>
<em>Knight, minstrel, abbot, squire, and guest. </em>
<em>There lay a parchment on her breast, </em>
<em>That puzzled more than all the rest, </em>
<em>The wellfed wits at Camelot. </em>
<em>'The web was woven curiously, </em>
<em>The charm is broken utterly, </em>
<em>Draw near and fear not,—this is I, </em>
<em>The Lady of Shalott.'</em>
She addresses herself, as <em>'I',</em> then repeats her name, <em>'The Lady of Shalott', </em>revealing that it was her who was last to speak.
I hope this helps you.