Pre-orders of the new iPhones are on track to top a record-breaking 10 million, according to analysts. Some models of the handset have already sold out.
While Apple hasn't disclosed exact sales figures, analysts reckon it has sold 4.5 million of the new iPhones already.
That's more than the 4 million it sold in the first pre-order weekend for the iPhone 6 and 6 Plus.
Apple spokesperson Trudy Muller told the Guardian: "Pre-orders this weekend were very strong around the world."
The huge sales are thought to be because of big demand in China, especially for the rose gold model. Apple only released its handset range in the region last October, after it had launched the iPhone 6 elsewhere in the world.
Here in Blighty, some models have already sold out. All colours of the 6S Plus are listed as shipping in three to four weeks.
The rose gold and space grey models of 6S are listed as shipping in two to three weeks, which would put them about one to two weeks behind schedule.
The other two colours should ship on September 25th, as originally planned.