The sentencing also came as the global powers are seeking to finalise a trade deal following more than a year of bruising negotiations, with the flood of Chinese fentanyl one of the sticking points.
US authorities say the synthetic opioid - which can be up to 50 times more potent than heroin - causes more than 100 deaths a day in the United States.
The court in northern Hebei province described the case as the first successful joint US-Chinese probe related to fentanyl smuggling, and US officials also hailed the verdict.
"As the success of the joint investigation demonstrates, Chinese and American investigators have the capacity to collaborate across international borders," Austin Moore, an attache for the US Homeland Security Department in China, said at a press conference with Chinese officials following the sentencing.
An official Chinese statement issued after the sentencing hailed the case as an "excellent model for the joint tackling of fentanyl-related crimes by Chinese and US drug enforcement departments."
China's narcotics bureau discovered in 2017 a criminal ring based in Shanghai and eastern Jiangsu province and seized 11.9 kilogrammes of fentanyl, acting on a tip-off from US border authorities, according to the court.
Of the nine people jailed in Hebei, one was given a death sentence with a two-year reprieve, which generally means a life term.
Two others received life terms for trafficking fentanyl and alprazolam - the hugely popular prescription anxiety drug branded as Xanax.
The nine defendants were brought in surrounded by guards and stood facing court officials to hear their sentences read.
The three defendants with the toughest sentences were "lured by high profit and huge demand" from US buyers, the Xingtai Intermediate People's Court said.
In November 2016, two of the defendants began advertising drugs through the internet using companies they had registered for pharmaceutical sales operations, the court said in a statement. In 2017 two other defendants - including Liu Yong, who was given the suspended death sentence - set up a processing lab where they illegally processed fentanyl and sold it to these companies to smuggle to the US.
Moore said officers in New Orleans obtained in August 2017 the contact details of a supplier in China known as "Diana".
The Americans then shared the information with Chinese counterparts and the investigation led to the arrests at the end of 2017, Moore said.