In an online travel blog for Vogue, the actress appears to have leaked the news that the pair are engaged.
"On our first day in Seoul, my fiancé, Michael Polish, and I venture out to discover Changdeokgung Palace," writes Bosworth.
She says nothing more about their romantic status, but does go on to describe exploring ancient towers, pavilions and beautiful secret gardens.
Bosworth, 29, was first spotted stepping out with Polish at a Coldplay concert in August 2011 in Los Angeles. They've since been seen at a number of events and hotspots.
Polish, 41, directed Bosworth in the upcoming film Big Sur about Jack Kerouac's three brief trips to a cabin on the Northern California coast.