"The last two years have been the most difficult for my family and I," Manafort said in his plea for compassion from the judge.
"To say I have been humiliated and ashamed would be a gross understatement," he said.
Before delivering his sentence, Ellis said that Manafort has "been a good friend to others, a generous person."
The judge added: "He has lived an otherwise blameless life."
Manafort had been convicted in the Virginia court last summer on eight counts of bank fraud, tax fraud and failing to file a foreign bank account report. The charges mostly pertained to Manafort's past work for Ukraine's Russia-backed president at the time, Viktor Yanukovych.
Manafort was not convicted on 10 other criminal counts in that case, which were deadlocked by the 12-person jury.
Manafort's lawyer argued in court that the amount of time Manafort spent talking to prosecutors — 50 hours in total — reflects significant cooperation in the government's investigation.
But Mueller's team said bluntly that Manafort's interviews only took so long because he misled them.
"Fifty hours with us was because he lied," prosecutor Greg Andres told Ellis. "He lied, so it took longer to provide the truth to him."
Manafort "did not provide valuable information to the special counsel that wasn't already known," Andres said.
In a sentencing memo last week, Manafort's attorneys argued that Manafort should receive a sentence "substantially below" the 19-to-24-year prison length suggested by federal guidelines. Manafort is a "first-time offender," they wrote, and noted that he admitted his guilt on separate charges launched by Mueller in Washington, D.C., federal court.
Ellis apparently agreed that the guidelines were too high, calling the calculated range "excessive."
Still, Ellis said before delivering the sentence that he was "surprised" he did not hear Manafort "express regret" in his remarks.
Manafort's attorneys also accused the special counsel of attempting to "vilify Mr. Manafort as a lifelong and irredeemable felon," as well as "spreading misinformation about Mr. Manafort to impugn his character in a manner that this country has not experienced in decades."
But Mueller countered in a Tuesday night filing that Manafort's request for leniency should be ignored at his sentencing, arguing that Manafort has not taken responsibility for his crimes. The special counsel also highlighted additional wrongdoing Manafort is alleged to have done since his cases began, including witness tampering and lying to investigators.
While Ellis had often been curt and impatient toward prosecutors during Manafort's three-week trial, most of his rulings before announcing Manafort's sentence appeared to favor the government's position.
Ellis reportedly shot down multiple objections from Manafort's lawyers regarding a pre-sentence report prepared by federal probation officials. The judge also declined to give Manafort any credit for accepting responsibility for his crimes.
Both the defense and the prosecution agreed to delay a decision about Manafort's restitution until after his second sentencing in D.C. next week.
Trump has consistently and aggressively denounced the Mueller probe as "illegal" and a "witch hunt" motivated by partisan politics. His fiery criticisms have raised alarm among Mueller's defenders, who suspect Trump may be considering a pardon for Manafort or other targets of the Russia probe.
"It's very sad, what happened to Paul," Trump said of Manafort in November. "I have not offered any pardons," he said at that time, but added, "I'm not taking anything off the table."
New York authorities are reportedly prepping charges against Manafort if Trump does pardon his crimes.