Alcohol consumption is an established risk factor for colorectal cancer (CRC). However, while studies have consistently reported elevated risk of CRC among heavy drinkers, associations at moderate levels of alcohol consumption are less clear. We conducted a combined analysis of 16 studies of CRC to examine the shape of the alcohol–CRC association, investigate potential effect modifiers of the association, and examine differential effects of alcohol consumption by cancer anatomic site and stage. We collected information on alcohol consumption for 14,276 CRC cases and 15,802 controls from 5 case‐control and 11 nested case‐control studies of CRC. We compared adjusted logistic regression models with linear and restricted cubic splines to select a model that best fit the association between alcohol consumption and CRC. Study‐specific results were pooled using fixed‐effects meta‐analysis. Compared to non‐/occasional drinking (≤1 g/day), light/moderate drinking (up to 2 drinks/day) was associated with a decreased risk of CRC (odds ratio OR: 0.92, 95% confidence interval CI: 0.88–0.98, p = 0.005), heavy drinking (2–3 drinks/day) was not significantly associated with CRC risk (OR: 1.11, 95% CI: 0.99–1.24, p = 0.08) and very heavy drinking (more than 3 drinks/day) was associated with a significant increased risk (OR: 1.25, 95% CI: 1.11–1.40, p < 0.001). We observed no evidence of interactions with lifestyle risk factors or of differences by cancer site or stage. These results provide further evidence that there is a J‐shaped association between alcohol consumption and CRC risk. This overall pattern was not significantly modified by other CRC risk factors and there was no effect heterogeneity by tumor site or stage. What's new? Heavy drinking is associated with increased colorectal cancer (CRC) risk, but there's debate about the impact of moderate drinking. Here, the authors conducted a combined analysis of 16 studies comprising 14,276 cases and 15,802 controls. By their analysis, drinking 1‐2 alcoholic beverages per day was associated with a reduced risk of CRC, compared with rare or no alcohol consumption. With 3 or more drinks per day, CRC risk rises. The authors suggest that moderate alcohol consumption may reduce inflammation and DNA damage, although they acknowledge that more research is needed to understand the biochemical mechanism at work.