Source: Sharecast
The high street chain said a selection of fashion ranges were now available to buy online for home delivery in England, Wales and Scotland.
More items, including beauty and homeware products, will also be made available "in the coming weeks", it confirmed.
The high street giant was forced to halt all online orders after hackers attacked over the Easter weekend in late April.
Click and collect and contactless payments were affected, shelves were left empty and some customer details were stolen, including addresses and dates of birth. Online orders were suspended a few days following the attack.
M&S has already warned that the attack will likely hit profits by around £300m in the current year.
In a brief statement, John Lyttle, managing director of fashion, home and beauty, said: "More of our fashion, home and beautify products will be added every day, and we will resume deliveries to Northern Ireland and click and collect in the coming weeks."
Russ Mould, investment director at AJ Bell, said M&S was taking a "step-by-step approach".
He continued: "The retailer will want to make sure everything is functioning smoothly before turning all the lights back on, as it cannot risk any further disruption to customers. It’s already having to work hard to regain their trust."
As at 1100 BST, shares in M&S were up 3% at 372p.