The World Health Organisation says Sierra Leone is free of Ebola transmissions, but will be under heightened surveillance for 90 days.
WHO Sierra Leone Representative Anders Nordstrom made the declaration on Saturday.
The organisation says that 42 days have passed - twice the maximum incubation period - since the last confirmed Ebola patient was discharged September 25.
Nearly 4000 people have died in Sierra Leone in the worst Ebola outbreak in history.
Weak leadership, shoddy supplies and infighting have worsened the battle against this outbreak of the virus, which has killed some 11,000 people mainly in Guinea, Sierra Leone and Liberia.
WHO has recorded seven new cases in neighbouring Guinea in the past 21 days.
