My Bed hit the headlines when it was shortlisted for the Turner Prize - and displayed at Tate Britain - in 1999.
Earlier this month the notorious work fetched £2.54 million at auction, a record for the artist, when it was purchased by dealer and White Cube gallery owner Jay Jopling.
It has now emerged that Jopling acquired the work on behalf of German industrialist and collector Count Christian Duerckheim, who has announced the long-term loan to the Tate for at least 10 years.
It is not yet known whether the bed will go on display at Tate Britain or Tate Modern and a gallery spokesman said that details will be announced in the autumn.
Count Duerckheim said: "I always admired the honesty of Tracey, but I bought My Bed because it is a metaphor for life, where troubles begin and logics die."
Tate director Sir Nicholas Serota said: "I am absolutely delighted that Count Duerckheim has agreed to loan such an important work to Tate for a period of at least 10 years.
"We look forward to displaying the work and are most grateful to Count Duerckheim for his generosity in creating an opportunity for visitors to see a work that now has iconic status."
My Bed was one of the key works of the 1990s Young British Artists (YBA) movement and earlier this month shattered the record for one of Emin's artworks at auction.
Now 51 and a CBE, Emin made the piece, complete with stained sheets and discarded underwear, in her Waterloo council flat in 1998.
The work captured her chaotic life after a bout of suicidal depression following a relationship breakdown.
Millionaire collector Charles Saatchi, who bought My Bed for £150,000 in 2000, sold it at Christie's.