Objective: Little research has evaluated trends in psychotropic prescribing and polypharmacy in primary care patients, especially those with dementia. We sought to examine this in Australia from 2011 to 2020 using the primary care dataset, MedicineInsight. Methods: Ten consecutive serial cross-sectional analyses were performed to evaluate the proportion of patients aged 65 years or more, with a recorded diagnosis of dementia, who were prescribed psychotropic medications within the first six months of each year from 2011 to 2020. This proportion was compared with propensity score-matched control patients without dementia. Results: Before matching, 24,701 patients (59.2% females) with, and 72,105 patients (59.2% females) without, a recorded diagnosis of dementia were included. In 2011, 42% (95% confidence interval [CI] 40.5–43.5%) of patients in the dementia group had at least one recorded prescription of a psychotropic medication, which declined to 34.2% (95% CI 33.3–35.1%;pfor trend < 0.001) by 2020. However, it remained unchanged for matched controls (36% [95% CI 34.6–37.5%] in 2011 and 36.7% [95% CI 35.7–37.6%] in 2020). The greatest decline in the dementia groups by medication class was for antipsychotics (from 15.9% [95% CI 14.8–17.0%] to 8.8% [95% CI 8.2–9.4%];pfor trend < 0.001). During this period, the prevalence of psychotropic polypharmacy (use of two or more individual psychotropics) also decreased from 21.7% (95% CI 20.5–22.9%) to 18.1% (95% CI 17.4–18.9%) in the dementia groups, and slightly increased from 15.2% (95% CI 14.1–16.3%) to 16.6% (95% CI 15.9–17.3%) in the matched controls. Conclusions: The decline in psychotropic prescribing, particularly antipsychotics, in Australian primary care patients with dementia is encouraging. However, psychotropic polypharmacy still occurred in almost one in five patients with dementia at the end of the study period. Programs focused on encouraging further reductions in the use of multiple psychotropic drugs in patients with dementia are recommended, particularly in rural and remote regions.