- David Sheridan has other uses. Please see David Sheridan (disambiguation) for other meanings.
"Never start a fight, but always finish it."
- – David Sheridan
The day before his entrance exams for Earthforce Academy, John had trouble falling to sleep. Knowing his son had an easier time falling to sleep when it rained, David went outside and sprayed water from a garden hose on the roof until John fell asleep.
In 2260, Sheridan was contacted by John from Babylon 5 who wanted some advice and assurance on an action he had to take. John was about to secede from the Earth Alliance and he couldn't tell his father, but he knew. Sheridan reminded his son about a lesson taught to him: "Never start a fight, always finish it." John warns him that President Clark's forces may come for him and Miranda, and Sheridan explains he understands they will have to go into hiding, but John should not worry about them.
During the rest of the Earth Alliance Civil War, the Sheridans went into hiding so that they would not be targeted by Clark's forces. Sheridan successfully evaded Clark's forces for many months, however, due to a rare blood disease, Sheridan required the Centauri drug tenasticin. When this information was leaked to Clark's men, Sheridan was tracked down and captured in a safe house just outside of Chicago, though Miranda was able to escape and hide with friends in Minneapolis. Sheridan was used to lure John away from the battle long enough to be captured by Clark-loyalists.
- Being John's father, David is also descended from Philip Henry Sheridan, a Union General of the US Army during the American Civil War.
- Before Kosh died in 2260, he appeared in a dream to John Sheridan, taking the form of David. An alien, native to the region of space where Babylon 4 disappeared, and who inhabited John Sheridan in 2259, also created in illusion of both David and his wife for John's benefit.
- David was not mentioned or seen during his son's final days in 2281, suggesting he may have passed away by that point.
- An uncredited performer who had no dialogue portrayed David in "Knives," while Rance Howard assumed the role in all subsequent appearances.
- "Knives" (David has no lines, appearing only as a hallucination)
- "Severed Dreams"
- "Interludes and Examinations" (Kosh appears as David in Sheridan's dream)
- "Rising Star"