"I was right on Mellouli's feet the whole way and it was extremely easy. If the whole race could have gone like that it would have been really nice but I think I backed off a bit in the middle," the Daily Mail quotes Fogg as saying.
"I think there was a breakaway which I couldn't see because I was too far back. It was just a matter on the last lap or two trying to take the person in front and then the person in front and then put the hammer down for the last lap.
"I am really happy with fifth, it's higher than I thought I could do."
Fogg also competed in the men's 1,500m freestyle at the Aquatics Centre, reaching the final in the event but coming in eighth there.