The driver was later found to have been shot, according to Los Angeles police, who were searching for a suspected gunman who fled the scene.
It was not immediately clear if the driver had been shot before or after the crash or why he drove into the crowd, a Los Angeles Police Department spokesman said.
Twenty-three victims were transported to local hospitals and trauma centers, according to police.
At least three were in critical condition after being injured along Santa Monica Boulevard in East Hollywood, the Los Angeles City Fire Department said in a statement.
Fire Captain Adam VanGerpen said that a line of people - the majority female - were waiting to enter a nightclub when they were struck by a Nissan Versa that also hit a taco truck and valet stand.
"They were all standing in line going into a nightclub. There was a taco cart out there, so they were ... getting some food, waiting to go in. And there's also a valet line there," said VanGerpen, a public information officer.
"The valet podium was taken out, the taco truck was taken out, and then a large number of people were impacted by the vehicle."
People inside the club came out to help in the minutes before emergency crews arrived, he said, to help the victims.
The driver, whose gunshot wound was found by paramedics, was taken to a local hospital.
Police did not identify him or disclose his condition.
The shooter was described as a man in a blue jersey with a silver revolver.
"This is under police investigation," VanGerpen said.
"This will be a large investigation with the LAPD."
The club, Vermont Hollywood, was hosting a reggae/hip hop event from 10pm to 2am, according to its online calendar.
A fight had broken out outside of the club prior to the incident, according to Maria Medrano, who was working a food cart outside.
Shortly after, Medrano said, the car hit a group of people standing outside.
She said she and her husband, who were both selling hot dogs outside, narrowly escaped after the car struck their stand, crushing it.
"The car stopped once it hit the hot dog stand, it got stuck there," Medrano told the Associated Press from the hospital.
"If not, I wouldn't be here to tell (the story)."
Medrano said she heard what appeared to be gunshots after the crash.
"Everyone started running," she said.
