Prosecutors had accused Papadopoulos of lying about "his contacts with Russians and Russian intermediaries during the campaign" - but in the court hearing, lawyers for him said President Donald Trump's actions were much worse with regards to the Russia investigation.
Earlier in the day, President Trump told reporters aboard Air Force One that he knew little about Papadopoulos, other than what he's seen in the news.
"I don’t know Papadopoulos, I don’t know. I saw him sitting in one picture at a table with me that’s the only thing I know about him," the President said.
"They got him, on I guess, on a couple of lies," Mr. Trump added.
Aides to the President have often dismissed Papadopoulos as a low-level volunteer, with one labeling him a 'coffee boy.'
Papadopoulos ran into trouble with the feds months before Robert Mueller was appointed to take over the Russia investigation, after the firing of FBI Director James Comey by President Trump.
"The defendant’s crime was serious and caused damage to the government’s investigation into Russian interference in the 2016 presidential election," the Special Counsel's office said in court documents.
"The defendant lied in order to conceal his contacts with Russians and Russian intermediaries during the campaign," the Mueller team added in a pre-sentencing memo.
Prosecutors say Papadopoulos "made material false statements and material omissions during an interview" with FBI agents on January 27, 2017.
"At the time of the interview, the FBI had an open investigation into the Russian government's efforts to interfere in the 2016 presidential election,
including the nature of any links between individuals associated with the Campaign and the Russian government, and whether there was any coordination between the Campaign and Russia's efforts," court documents state.