Legal Question in Landlord & Tenant Law in California

It depends on the terms of the lease. Most leases have either a provision that they auto-renew if neither party gives notice they do not intend to renew, or more commonly a provision that converts the lease to a month-to-month rental at the end of the term if neither party gives notice they do not intened for it to convert. If it has either of those types of provisions, you would have to give notice in accordance with the terms of the lease. If, however, it is just a straight lease for a term with no renewal or conversion provisions then not only is no notice necessary before vacating, the tenant MUST vacate unless arrangments are made for a new lease or rental agreement.