Aidan O'Brien is confident
The six-year-old was a dominant winner of the two and a half-mile showpiece in 2016 and was beaten just a short-head by Big Orange in a pulsating climax to last year's renewal.
O'Brien has followed a tried and tested route with his charge this spring, saddling him to win both the Vintage Crop Stakes at Navan and the Saval Beg at Leopardstown; the same two races he contested last year.
The Ballydoyle handler, who is bidding for a record eighth Gold Cup victory, said in a stable tour on www.attheraces.com: "Everything has gone well with him since his last run at Navan.
"We are as happy with him going into the Gold Cup as we have been with him in any of the other years he has gone there."
The horse widely regarded as Order Of St George's biggest threat is the four-year-old Stradivarius.
John Gosden's colt won the Queen's Vase at last year's Royal meeting and went on to lift the Goodwood Cup later in the summer.
He was narrowly beaten in the St Leger, finished third behind Order Of St George in Ascot's Long Distance Cup in October and made an impressive reappearance in last month's Yorkshire Cup.
Gosden said: "He's in great nick and he has come out of his win at York very well.
"It will be a helluva test; the two and a half miles. Once he goes beyond two miles, it is uncharted territory.
"We are very hopeful he will get the trip. If he doesn't, we know what we will do; we will go to a Goodwood Cup and prepare for a Melbourne Cup;
Assessing the opposition, the trainer added: "Order Of St George is obviously a good horse, as is the Aga Khan's horse (Vazirabad) and the horse that won the Sagaro (Torcedor).
"It's got great depth in it this year. So often the Gold Cup can be a little bit thin on quality, but there is a lot of depth there and it's an exciting Gold Cup this year.
Torcedor was fifth in last year's Gold Cup and returns on the back of a runaway victory in the Sagaro Stakes.
Trainer Jessica Harrington has won the Cheltenham Gold Cup, Champion Hurdle and Champion Chase; but is still seeking a first Royal Ascot success.
Speaking ahead of another leg of the Qipco British Champions Series, Harrington said: "I first went (to Royal Ascot) when I was about 17. It's a great meeting, a fantastic week whether you are working or going for the fun.
"It would be lovely to have a winner there; if you are a trainer you want to win at Ascot, like at Cheltenham or Punchestown. They are the ones that matter.
Of Torcedor, the trainer added: "Torcedor is in great form.
"I think he's a better horse than this time last year. Physically he has done very well and he's good mentally.
"He's run very well every time he's been to Ascot; it's a case of courses for horses."