The Government had already pledged £2 million to help efforts in Sierra Leone and Liberia but has now increased its assistance package to £5m, International Development Secretary Justine Greening said.
Earlier, Foreign Secretary Philip Hammond chaired a meeting of the Government's Cobra emergencies committee to discuss the situation in West Africa.
So far more than 1,700 people have been infected in Sierra Leone, Liberia, Guinea and a handful of probable cases have been identified in Nigeria. A total of 932 people have died during the outbreak, according to the World Health Organisation (WHO) show.
The Department for International Development said the new funds, which will be given to organisations working to tackle the crisis, will help provide specialist care to those affected, improve monitoring and tracking of the disease and provide better health information to rural communities.
Ms Greening said: "It is absolutely critical that the UK helps to make sure the Ebola outbreak is contained. We will continue to work with partners like the WHO, the Red Cross and Unicef to limit this awful disease."
On the Cobra meeting, a Foreign and Commonwealth Office spokesman said: "Medical advice remains that the risk to the UK is very low."