The speaker in the poem directly addresses the Grecian urn he is gazing at, calling the urn you "bride of quietness" and "foster-child of silence." The speaker also calls it a historian, because it captures in the picture displayed on it a moment of the ancient Greek past.

I believe the speaker in the poem is Keats himself, not a persona. The narrator expresses the thoughts of Keats, who at the time of composition was nursing his brother Tom, who was dying of tuberculosis. Keats was soon to contract the fatal disease himself. Mortality must have been much on his mind, and the verses express the poet's ecstatic desire to be one of the painted figures frozen on the urn. As he states in the poem, using the word "happy" repeatedly, it would be delightful to be a piece of art, an image always young and in love, always in a springtime setting, always en route to a festival.

As Keats puts it in the ecstatic third stanza, reinforced with exclamation points that convey his strong emotion:

Ah, happy, happy boughs! that cannot shed
Your leaves, nor ever bid the Spring adieu;
And, happy melodist, unwearied,
For ever piping songs for ever new;
More happy love! more happy, happy love!
For ever warm and still to be enjoy'd,
For ever panting, and for ever young

Keats speaks directly to the urn, but his true audience is the rest of us, who are also invited to ponder if it would be better to be frozen as a picture on an urn or to be a mortal being who will suffer, age, and die. His voice in this poem is filled with excitement and desire as he imagines what is like to be on the urn. Urn and self seem to merge and only gradually does the poet pull away.

An apparent supervision of ‘Ode on a Grecian Urn’ reveals that the voice of the poem is that of the poet.  However many critics do contradict with this observation. Many scholars do take into consideration the last two ambiguous lines: ""Beauty is Truth, Truth Beauty,"—that is all / Ye know on earth, and all ye need to know” and argue that this is the voice of the urn. There are also a number of critics who say that the last two lines are reader's response. However, most of the critics do believe that in the poem there is a singular voice and that voice is the voice of the poet. According to this interpretation the last two lines are addressed to the urn by the poet. The “Ye” of the final line refers to the urn and ““Beauty is Truth, Truth Beauty”” is a knowledge that the urn communicates to the poet through its “Attic shape”.