The anti-camping law bans people from setting up tents on public land and sleeping on sidewalks.
Newport Beach public works crews had cleared out tents and homeless people at the pier by 9 a.m. Thursday.
Police patrolled popular spots, such as the pier and Balboa Island, to make sure the areas remained cleared.
Before the new municipal code went into effect, officers went around talking to people to inform them of what was coming.
"The city of Newport Beach and the Newport Beach Police Department are working together to ensure the safety of the community and everyone who comes and visits," Sgt. Steve Oberon said in a video posted on the police department's Facebook page Monday.
The law comes after Gov. Gavin Newsom threatened cities and counties to clean up encampments or risk losing state funding.
The city of Anaheim has already put in place a similar ban. For those who are displaced by similar bans, the Orange County Rescue Mission says the organization is ready to help.
"We have bed availability at the Rescue Mission. We're a long-term program to help people get back on their feet and achieve self-sufficiency, " OC Rescue Mission CEO Bryan Crane said.
The new ordinance doesn't require Newport Beach to offer services to those who have been forced to move, however, the city is still offering help to individuals who want it.