Some celebrity endorsements of cryptocurrencies have run into trouble. In 2017, the Securities and Exchange Commission cautioned that some famous people were hyping the virtual currency sales known as initial coin offerings without disclosing that they had been paid to promote them. The commission has since settled charges against the boxer Floyd Mayweather Jr., the music producer DJ Khaled and the actor Steven Seagal.

Social media influencers and e-sports stars have also been linked to shady cryptocurrency schemes, accused of pumping up coins just before their value crashes.

Coin Cloud’s chief marketing officer, Amondo Redmond, said he hoped Mr. Lee’s stature would help elevate the industry by delivering something “more than just cool creative, but that is really at the forefront of digital currency becoming mainstream.”

“It’s more than just adding a celebrity face,” he said.

Mr. Lee, who won an Oscar in 2019 in the best adapted screenplay category for “BlacKkKlansman,” has worked on ads for Capital One, Uber and, most famously, Nike. In the 1980s and 1990s, he directed and starred in commercials for Air Jordans, playing his cinematic alter ego Mars Blackmon opposite Michael Jordan.

“That was lightning in a bottle,” Mr. Lee said from a flight bound for the Cannes Film Festival, where he is the first Black person to lead the festival jury.

He declined to say how much he had been paid for the Coin Cloud commercial, but noted that “if anyone’s known my body of work over the last four decades, you kind of know about the way I see the world, and when they approached me, it fit in line.”

As the coronavirus pandemic continues to highlight financial disadvantages for people of color, Mr. Lee hopes to promote cryptocurrency as neutral to race, gender, age and other identifying characteristics.