Frequent gastroesophageal reflux (GER) causes chronic inflammation and damages esophageal mucosa, which can lead to Barrett’s esophagus. It has also been consistently found to be a strong risk factor for esophageal adenocarcinoma. The prevalence of GER appears to vary; however, population-based Australian studies investigating the symptoms are limited. This study aimed to estimate the population prevalence and identify the determinants of frequent GER symptoms in the Australian population. Self-reported information on the frequency of reflux symptoms were collected from 1,580 adults from a population register. We estimated age- and sex-standardized prevalence of occasional (<weekly) and frequent (>weekly) GER symptoms in the Australian population. We also estimated adjusted prevalence ratios (PR) for GER symptoms associated with demographic and lifestyle characteristics. The standardized prevalences of GER symptoms were 10.4% and 38.3% for frequent and occasional symptoms, respectively. Compared with participants with body mass index <25, those with body mass index >35 had almost 90% higher prevalence of frequent GER symptoms (PR 1.89; 95% confidence interval [CI] 1.13–3.16). Similarly, the prevalence of frequent GER symptoms was significantly higher among regular users of aspirin or other non-steroidal anti-inflammatory drugs than never users (PR 1.71; 95%CI 1.08–3.16) and regular consumers of medium to well-done barbecued meat (PR 1.75; 95%CI 1.10–2.80) or fried food (PR 2.69; 95%CI 1.66–4.35). The prevalence of frequent GER symptoms was significantly lowered with regular physical activity (PR 0.46; 95%CI 0.32–0.66) and Helicobacter pylori infection (PR 0.53; 95%CI 0.35–0.80). We found no evidence that frequent GER symptoms were associated with smoking, alcohol, spicy food, or coffee consumption. Our results confirm that GER symptoms are common and that frequent GER symptoms are associated with a range of modifiable lifestyle factors.