General objective of this lecture is to explain Routing Algorithms. Here briefly describe on the Optimality Principle, Shortest Path Routing, Flooding, Distance Vector Routing, Link State Routing, Hierarchical Routing, Broadcast Routing, Multicast Routing, Routing for Mobile Hosts and Routing in Ad Hoc Networks. Finally discuss on Store-and-Forward Packet Switching and Implementation of Connection-Oriented Service in terms of Routing Algorithms.