The two boys, both aged 17, spent Monday night in a police cell after being caught with items including a fragment of a razor, a piece of spoon, buttons and two pieces of glass, believed to have once belonged to inmates at the Nazi German camp.
A police spokesman had said earlier on Tuesday that they could face up to 10 years in prison.
Krzysztof Lach, a spokesman for the regional police in Krakow, southern Poland, said the two had pleaded guilty at a court hearing. They were given suspended sentences and ordered to report to a police station back in Britain at regular intervals, he said.
Auschwitz, which is near Krakow, has become a poignant symbol of the Nazi German Holocaust that claimed six million Jewish lives across Europe during World War Two.
Around 1.5 million people, mainly European Jews, were gassed, shot, hanged or burned at Auschwitz during the war. Part of the site is now a museum.
The pupils were spotted acting suspiciously on Monday afternoon near a building where Nazi German guards had stored prisoners’ confiscated belongings, said a museum spokesman.
Perse School, a fee-paying school in Cambridge, England, where the two boys are studying, said the pair had attempted to keep some items of historical importance which they found on the ground at the site.
“We understand they have explained that they picked up the items without thinking and they have apologized unreservedly for the offense they have given, and expressed real remorse for their action,” a Perse School spokesman said.
Curators at the museum on the Auschwitz site have for years struggled to stop visitors pilfering artifacts as souvenirs.
In 2010, a Swedish man was jailed for orchestrating the theft of the infamous “Arbeit macht frei” (Work sets you free) sign from the entry gate of the Auschwitz site.