The poet, from Bellaghy, County Londonderry, died at a Dublin hospital on 30 August 2013, at the age of 74.
The inscription on his headstone is a line from Heaney's poem The Gravel Walks, which he used in his 1995 Nobel prize acceptance speech.
It reads: "Walk on air against your better judgement."
Heaney's memorial is located in a corner of the graveyard adjoining St Mary's parish church in Bellaghy, close to that of his parents and other members of the family.
He was awarded the Nobel Prize for Literature "for works of lyrical beauty and ethical depth, which exalt everyday miracles and the living past".
Heaney previously explained why he chose the quotation to include in his Nobel acceptance lecture, as the Irish News reports.
"A person from Northern Ireland is naturally cautious," he said. You grew up vigilant because it's a divided society. My poetry on the whole was earth hugging, but then I began to look up rather than keep down.
"I think it had to do with a sense that the marvellous was as permissible as the matter-of-fact in poetry."
The former professor of poetry at Oxford University said The Gravel Walks focused on heavy work as well as the "paradoxical sense of lightness" when lifting heavy things. It also alludes to a popular traditional Irish reel of the same name.
"I like the in-betweenness of up and down, of being on the earth and of the heavens," he added.
"I think that's where poetry should dwell, between the dream world and the given world, because you don't just want photography, and you don't want fantasy either."
The Gravel Walks, features in Heaney's collection, The Spirit Level, which also includes a poem dedicated to his brother, Hugh, entitled Keeping Going.
Hugh told the BBC he regularly visited the grave and encountered people from across the world who travelled to pay their respects to the poet.
"Seamus wrote a lovely poem about myself which I'm very proud of and is very moving," he said.
"I suffer from epilepsy and Seamus wrote a poem for me in The Spirit Level called Keeping Going, I was at the launch of the book when he said this is a poem for Hugh.
"That was lovely and I'm very proud."
Hugh said that what was heartwarming about his brother was that despite his outstanding literary career and stratospheric success "his feet never left the ground".
A headstone for Seamus Heaney's grave, inscribed with a quotation from one of his poems, has been unveiled ahead of the second anniversary of his death.