The news emerged as the former 30 Rock star was released from hospital, five weeks after the crash.
Morgan will continue his recovery at home with an “aggressive outpatient programme”, spokesman Lewis Kay said.
The lawsuit, filed in US District Court in New Jersey, claims Wal-Mart was negligent when a driver of one of its trucks rammed into Morgan’s limousine van on June 7. The complaint claims the retail giant should have known the driver had been awake for over 24 hours, and that his commute of 700 miles (1,125km) from his home in Georgia to work in Delaware was “unreasonable”. It also alleges the driver fell asleep at the wheel.
The complaint adds: “As a result of Wal-Mart’s gross, reckless, willful, wanton, and intentional conduct, it should be appropriately punished with the imposition of punitive damages.”
Morgan’s lawsuit seeks a jury trial and punitive and compensatory damages.
In a statement, Wal-Mart reiterated that it was “co-operating fully” in the investigation. “We know it will take some time to resolve all of the remaining issues as a result of the accident, but we’re committed to doing the right thing for all involved.”
The wreck killed 62-year-old comedian James McNair, who went by the name Jimmy Mack. Another comedian, Ardley Fuqua, and Jeffrey Millea, who were injured as passengers in the limo, are also named as plaintiffs.
Morgan suffered a broken leg and ribs in the crash. Fuqua is recovering from crash-related injuries.
Truck driver Kevin Roper, 35, of Jonesboro, Georgia, has pleaded not guilty to death by auto and assault by auto charges. A criminal complaint also accuses him of not sleeping for more than 24 hours before the crash, a violation of New Jersey law.
A report by safety investigators said Roper was driving at 65mph in the 60 seconds before he slammed into the limo van. The speed limit is 55mph and was lowered to 45mph that night because of roadworks.