Yes, in South Dakota a landlord cannot evict a tenant “for no reason” while a fixed-term lease is still in effect; they must have legal cause (like nonpayment of rent or a lease violation) to seek eviction before the lease agreement ends.
However, if there’s no lease or the lease has expired, the landlord doesn’t need a separate reason to end the tenancy. In those cases (such as a month-to-month tenancy), the landlord can terminate without cause by giving the tenant proper written notice (typically at least 30 days). After notice, the landlord must still go through the formal eviction process in court, they can’t remove a tenant without a court order.
The information for this answer was found on our South Dakota Eviction Process answers.