Britain was among several Western countries which closed their embassies on August 4 following US warnings of an Al-Qaeda attack. A few days later it withdrew all diplomatic staff.
Ambassador Jane Marriott announced on Twitter: "Hello Yemen. It's great to be back... Looking to reopen the embassy in the next couple of days. Watch this space."
The alert was reportedly linked to the interception of communications between Al-Qaeda leader Ayman al-Zawahiri and the leader of the group's Yemen-based affiliate, Nasser al-Wuhayshi.