Inclusion Criteria:  Patients with advanced cancer Age ≥ 21 years old  Fulfil All Three Diagnosis of Delirium:  Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria for delirium Memorial Delirium Assessment Scale (MDAS)©1996 > 13 Richmond Agitation-Sedation Scale (RASS) Score +1 to +3 Able to consume medications orally Prognosis > 48 hrs (Clinician Estimate)  Exclusion Criteria:  Parkinson's Disease or Vascular Parkinsonism Dementia with BPSD and active behavioral issues Chronic Schizophrenia on regular Anti-psychotic medications Taking any regular Benzodiazepines* or any Anti-psychotic** medications Known allergy to Haloperidol or Olanzapine History of Substance Abuse Known Prolonged corrected QT interval (QTc) Syndrome (In Patient's Medical History) Prognosis < 48 hours (Clinician's Estimate) Unable to consume oral medications Richmond Agitation and Sedation Scale (RASS) Score +4 (Too agitated and will require Parenteral Anti-psychotics and/or Benzodiazepines) * e.g. Lorazepam, Alprazolam, Clonazepam, Midazolam **e.g. Haloperidol, Risperidone, Quetiapine, Olanzapine