A Class C IP Checker tool is important because it allows users to check the class of a given IP address. IP addresses are divided into classes, with Class A, B, and C being the most commonly used. Each class has a specific range of IP addresses that it can use, and the class of an IP address determines how many hosts it can support. By using a Class C IP Checker tool, users can determine if an IP address is within the range of a Class C IP address, which is important for network configuration and troubleshooting. Additionally, Class C IP Checker tools can also be used to check for duplicate IP addresses and identify potential IP conflicts on a network.