Dr John Sentamu's written to the Prime Minister after hearing the case of Andrea Gada who died after being hit by a car in Eastbourne just before Christmas.
Her parents Wellington and Charity want the child's grandparents to attend the funeral but they've been refused permission to travel here due to visa issues.
It's claimed the reason for their refusal was that they couldn't show a regular income and there was a danger they would go into hiding upon arrival.
According to the Guardian, in his letter to Mr Cameron, the Archbishop said: "Having read about the situation, I feel sure that you will understand the need, in this instance, to intervene to ensure that the [grandparents] are able to attend this tragic funeral."
The family are being supported by their local MP Stephen Lloyd who has personally offered to guarantee the grandparents' departure from the UK after the funeral.
He's also table an Early Day Motion asking the Prime Minister and Home Secretary to intervene.
The family will hand a petition with over 94,000 signatures on to 10 Downing Street today.
They say having the extended family at the funeral is important to them for both 'cultural and religious' reasons.
The local community has so fair raised £5,000 for the travel costs.