The appointment will be made official on Thursday following a signing ceremony, the UNDP said in a statement.
"UNDP Bangladesh will appoint Mr Mashrafe Bin Mortaza as the UNDP National Goodwill Ambassador for Youth in Bangladesh," the release stated.
Mashrafe, who is currently the ODI and Twenty20 skipper, said that he had received the proposal a month ago and was extremely excited to receive the opportunity.