The change matches a new recommendation from Orange County, Florida as it phases out COVID-19 restrictions.
L.A. County theme parks can now increase their capacity to 35 percent.
The CDC still recommends that people aged 2 and older wear masks, but the Cedar Fair parks are only requiring masks for guests who are at least 10 years old.
The looser mask standards also mean guests do not have to wear face coverings while outdoor and physically distant from other parties.
An unexpected change to California guidelines is being interpreted by theme parks to allow vaccinated out-of-state guests.
The park says it will announce its full slate of COVID-19 protocols for 2021 on April 26.
Knott's Berry Farm is offering season passes for $101, which is less than a 1-day Disneyland ticket.
Guests can now remove masks in outdoor spaces where maintaining six feet of distance between other parties is possible.