Freshwater fish were used to examine how habitat quality, conspecific density, and season were associated with the cortisol stress response. Using pumpkinseed (Lepomis gibbosus) I tested whether glucose and cortisol concentrations varied relative to habitat complexity and conspecific density. Overall, neither factor had a significant effect on the GC stress response but, during the habitat experiment, fish collected from a littoral site had significantly higher concentrations of maximum glucose, glucose responsiveness, and maximum cortisol. Using central mudminnow (Umbra limi) from streams differing in habitat quality, I tested whether cortisol levels varied relative to habitat quality and season. Overall, only season had a significant effect on cortisol levels. This thesis indicates that polymorphism and season should be considered in stress-related studies. Moreover, the lack of association of GCs in fish sampled from habitats of differing quality emphasizes that human-perceived differences in habitat quality may not yield individual-level differences in stress.