A proximity-based reminder system includes one or more proximity detectors for determining whether a distance between two or more paired electronic devices satisfies various criteria. Data transmissions across a wide area network (WAN) are used to determine whether a distance between paired devices satisfies a first proximity condition. Transmissions across a local area network (LAN) are used to determine whether the distance between the paired devices satisfies a second proximity condition. When the first and second proximity conditions are satisfied, the proximity-based reminder system issues a reminder alert notification to one or more of the paired devices.