"Walking Disaster" is the second single from Sum 41's 2007 studio album, Underclass Hero. The song has been released as the second single from the album, and was released on July 23, 2007. The band performed the song on The Tonight Show with Jay Leno on July 24, 2007.

Written by Deryck Whibley, "Walking Disaster" is a classic, upbeat pop-punk song, drawing similarities from "March of the Dogs" (another song on the Underclass Hero album). According to Whibley, the song illustrates his tattered childhood and his reflections as an adult. The song, being somewhat chronological, opens with “Mom and Dad both in denial, an only child to take the blame”, a vision of Whibley’s past, damaged by his conflicting parents. "Walking Disaster" ends on an optimistic note, “I can’t wait to see you smile, wouldn’t miss it for the world”, expressing his maturation as an adult, in the light of being able to see things differently and ultimately, understanding his childhood.

Walking Disaster is a song that captures the concept of “confusion and frustration of modern society”, the underlying theme in “Underclass Hero”.