The role will be filled by James Richardson, who will also remain as the Treasury’s director of public spending and chief micro-economist.
Science lobbyists have long urged the Treasury to appoint a chief scientific adviser but the timing of the decision was unexpected.
Andrew Miller, chair of the Commons Science and Technology Committee, welcomed the appointment.
“It is essential that all departments across Whitehall receive the best natural and social scientific advice possible, especially at a time when difficult decisions are being made about spending priorities,” he said.
Mr Miller added that he would invite Dr Richardson, who has an economics degree from the London School of Economics, to appear before the committee as soon as possible.
Imran Khan, director of the Campaign for Science and Engineering, said the science community “desperately needs someone within the [Treasury] who can talk about how critical a long-term investment strategy for science and engineering is for the UK's future”.
He said he was not concerned that Dr Richardson was not a natural scientist or an academic as long as he was given enough independence to carry out his role and was able to join the network of chief scientific advisers.
“The key is to have someone who appreciates the use of evidence in a scientific context and the wider need for there to be an understanding of scientific and science investment issues within the Treasury,” he said.
“Ultimately we would like to see a fully independent, external, appointment but for now we are encouraged that the precedent has been set and there will be someone who is charged with being a chief scientific adviser at the Treasury.”
During a House of Lords debate earlier this week, Baroness Wilcox, parliamentary under secretary for business, innovation and skills, said Dr Richardson’s other departmental duties meant he was “at the heart of the decision-making process in the Treasury, which should be a very good thing”.
But Lord Willis of Knaresborough, a member of the Lords Science and Technology Committee, said peers should “not get too excited” by the announcement, because it was not clear how much time Dr Richardson would have to carry out the role.
During the debate peers also expressed concerns about the downgrading of the Ministry of Defence chief scientific adviser post when the current incumbent retires, and about the failure of the Department for Transport and Department for Business, Innovation and Skills to fill their vacant joint position.
Baroness Wilcox said the departments were “exploring the possibility of a shared role with another government department to take advantage of the synergies and overlaps between their science, technology and research interests”.