Systems and methods for mitigating drowsy and/or sleepy driving may include utilizing vehicle-related and wellness-related telematics to detect and/or predict drowsy and/or sleepy driving states of a driver of a vehicle and take mitigating actions to thereby increase the safety of the driver and other people and/or vehicles in the vicinity of the driver's vehicle. Vehicle-related telematics data and wellness-related telematics data (which may include sleep data) may be collected via sensors that disposed on-board the vehicle, in the vehicle's environment, and at a personal health/fitness tracker of the driver. The collected data may be collectively interpreted to detect, predict, and/or otherwise discover information relating to a drowsy and/or sleepy state of the driver, and one or more mitigating actions may be automatically performed based on the discovered information to thereby mitigate undesirable effects of drowsy/sleepy driving and increase driving safety.