Singleton is to start his role in January, having recently announced his departure from ITV after 24 years. He replaces James Helm, who left DfID earlier this year to join Portland as a partner in its international team in London.
Singleton has held a number of senior roles at ITV News, including head of foreign news, Westminster news editor and home and foreign news editor.
He has covered major global events including the 2003 Iraq War and the Asian Tsunami, along with six UK general elections. He won several BAFTA awards and other accolades during his career.
Singleton said: "During my career in broadcasting I’ve seen first-hand the impact of global problems resulting from chronic poverty, conflict and natural disasters. I’ve worked alongside the best in the business at ITV News, and now look forward to doing the same with new colleagues at DfID."
In August, PRWeek reported that Robert Oxley, previously head of media at the pro-Brexit campaign group Vote Leave, had joined DfID as a special adviser.