Justin Welby said the couple’s obvious love for each other and “profound sense of commitment” provided a “model” for the nation. 

The couple’s wedding next year will be “no tick-box exercise”, he added.

Speaking on BBC Radio 4’s Today programme, Dr Welby said: “I am very, very sure after conversations that this is no tick-box exercise, 'we ought to get married in a church'.”

Dr Welby has already given his approval for divorcee Miss Markle to marry Harry in a church.

The couple announced their engagement on November 27 after dating for just over 18 months.

They are due to tie the knot at St George’s Chapel, Windsor Castle, in May.

Dr Welby continued: “There is a profound sense of commitment, of seriousness, both about faith and their lives together, which is quite inspirational.

“It’s important because people look at it and see a model of how two people commit their lives to one another before God in the presence of millions of people.

“It’s always a beautiful moment - every wedding is profoundly beautiful. Even when you drop the rings it’s still a very moving wedding.”

He refused to confirm whether he would be conducting the ceremony.

But he made it clear he was at their disposal, saying “I think that’s up to them.”

He revealed he was looking forward to the big event, saying it would be “fun”.

He warned that at a recent wedding of one of his aides he managed to misplace a ring, sparking a hunt until it was discovered having rolled under a chair. 

He joked it would make ‘entertaining television’ if he repeated the blunder.

The Prince and Miss Markle, who divorced her first husband film producer Trevor Engelson in 2013, will marry at St George’s Chapel in the grounds of Windsor Castle because it is a place “close to the couple’s hearts”, it was revealed last month.

The pair shunned a larger wedding at Westminster Abbey or St Paul’s for the more intimate church service at St George’s, where Harry’s father Charles had a blessing after marrying Camilla in the nearby Guildhall in 2005. 

The couple have not given an exact date for their ‘fun and joyful’ wedding yet, but it is likely to be on TV.

The royal family will pay for the event, including music, the flowers and the reception. 

The Church of England agreed in 2002 that people could remarry in church under strict conditions. 

Divorcees are asked questions to ensure their previous marriage has been fully resolved and “past hurts” are healed.

The last time a senior royal wanted to marry an American divorcee, it sparked a constitutional crisis. 

Edward VIII – Prince Harry’s great-great-uncle – had to abdicate in 1936 to wed American socialite Wallis Simpson. 

But members of the Royal Family are no longer barred from marrying divorcees.