Using the online giant could save up to £100,000 a year, but local firms lose the business.
The States says its contracts for stationery were coming to an end last year and so it reviewed its procurement process.
Both local and off-island suppliers were invited to tender.
Those on island were given a preferential weighting, because of the value of their business to the Guernsey economy.
However, Amazon won, and has a 'framework agreement' to supply the States of Guernsey.
This move, the States says, could save up to £100,000 a year and it is no different to many people who opt to buy from the retailer:
“We use Amazon in the same way, and for the same reasons, that thousands of individuals and families use Amazon across the island.
"These are low value consumable items, often bought repetitively and across the business this amounts to several thousand transactions annually.
"It is therefore important that we can buy these efficiently and competitively."

Scorecard for people in Guernsey to monitor their alcohol intake
Plans to sell Guernsey rectory
Thousands of new species discovered in Guernsey’s freshwater habitats
Guernsey Post to end air deliveries
Channel Islands Pride: What's on where?
18 months before work can begin on resurfacing Alderney's runway
Guernsey man reflects on surviving 9/11 on the 25th anniversary
Temporary traffic lights removed from key St Peter Port route sooner than expected