Answering a question in the House of Commons he said he's not convinced it would be effective.
He was responding to a request from Christian Tory MP Fiona Bruce who highlighted the persecution against believers in Sri Lanka, Nigeria, Cameroon, Pakistan and Iraq.
She asked what the Government is doing to stop it and questioned whether it was time for the UK to appoint a global ambassador for religious freedom.
In his response, Mr Clegg said: "I am sure everybody is shocked not only by the news but by the litany of abuse, persecution and violence that is inflicted on Christians and all religious denominations that are persecuted minorities around the world.
"The Government, through bilateral engagement and working with partners in international organisations, funding projects, and providing religious literacy training for Foreign and Commonwealth Office staff, do a lot to counter this.
"The question whether we should go further-of course, we should always keep an open mind on this-and create an envoy or an ambassador on religious freedom is not quite as straightforward as she implies.
"Other countries that have taken that step have found that those ambassadors and envoys are excluded from visiting certain countries. That is why the best course of action at present is for each of the Foreign Office Ministers to retain the responsibility for promoting freedom of religion and belief in the areas of the world which they cover."
The comments come as Open Doors, an international charity supporting persecuted Christians, reveals its worst countries for persecution.
For the 13th year in a row, North Korea has come out on top of the organisation's World Watch List.