Background and Aims: Complexity is widely believed to be a positive trait in wine, but its definition remains ambiguous. The present study aims to assess how complexity in wine is perceived by social drinkers and experts, especially which attributes are most linked to their assessment of complexity. Methods and Results: Three young single varietal wines, Merlot, Cabernet Franc, Cabernet Sauvignon, and three 50–50 blends of these were used. Eighty-seven participants, comprising three expertise levels, tasted all six wines blind, then rated the perceived complexity, liking, intensity, familiarity, quality, and willingness to pay, as well as listing five flavour descriptors that best matched each wine. Linguistic analysis on the choice of flavour descriptors by participants revealed that greater complexity was associated with winemaking flavours, especially oak. Further analysis demonstrated that complexity was not independently correlated with willingness to pay, but was predicted by a combination of perceived attributes (quality, liking) as well as participant expertise. Conclusions: Wine complexity was revealed as a multi-faceted concept that involved the perceived attributes in the wine (quality, intensity, liking) as well as being influenced by participant background (age, gender) and even by environmental context (specifically the order in which the wines were tasted). Significance of the Study: We demonstrated how complexity and associated willingness to pay were assessed by people of different expertise levels, using both numerical ratings and linguistic analysis. We also tested for the first time the role of blending on perceived wine complexity.