The Duke of Sussex, 37, was the only senior member of the royal family not to attend yesterday's memorial.
It was rumoured Prince Harry was at home with his wife, Meghan Markle and two children in Montecito, California, where they own an £11 million mansion.
The service began at 10.30am in the UK - 2.30am at the Prince's home.
It is unknown if he watched the service, which was broadcast live.
Harry did make an appearance during the coverage of the service in a resurfaced clip from the documentary 'A 'Unique Portrait' of Prince Philip and his life'.
The Duke, who is due to travel to Holland in a fortnight to attend the Invictus Games, refused to travel over a row about his security.
Harry is currently pursuing a legal challenge against the Home Office after being told he would no longer be given the personal protective security he was once afforded as a senior royal when back in the UK.
His reasoning to stay away from his grandfather's memorial was branded "pathetic" by former royal protection officer Richard Griffin, who spent 14 years guarding the Duke of Edinburgh.
He said: "Prince Philip was their grandfather, so William has obviously had a great training from him and is going to learn examples from him. I just hope Harry gets some of these things in his mind.
'It [Harry not being here] was a big disappointment for everybody. People were talking about it. Certainly around where I was, people were saying he should have been here.
'All this nonsense about how he couldn't get protection, as far as I'm concerned, that was a pathetic excuse. He should've been here to honour his grandfather."
