The answer is no. You do not always need to give notice. For example, if the tenant dies, or they are a resident employee of yours and you have released them from employment, or a fixed-term lease has expired, then no notice need be given.
In the case of the fixed-term lease, let’s say the tenant has a lease for one year and that year comes and goes. If you don’t accept rent from them after the expiration date, and you haven’t given them permission, then you can file the Unlawful Detainer suit without notice. However, leases often have provisions in them that provide for a fixed-term lease to become a month-to-month lease after the expiration date. As a general rule, when in doubt, issue notice. Or better yet, hire a lawyer who knows this area of law and don’t waste your valuable time and money.