Elliott was never charged over the 2016 incident, but a panel of advisers recruited by the NFL during its year-long investigation found him in breach of the league's Personal Conduct Policy.
The investigation began over a year ago after his ex-girlfriend Tiffany Thompson accused him of physical violence. Elliott faced a domestic violence claim along with a motley of off the field mishaps violating the personal conduct policy.
The loss of Elliott is a big blow for Dallas' playoff and Super Bowl hopes.
"In addition, the NFL's own medical experts concluded that many of her injuries predated the week in question and likely occurred during a period of time when Mr. Elliott was not in contact with the accuser". By being the subject of disciplinary action from the league, Elliott also will have to pay back some of his signing bonus of $16.35 million - about $1.44 million.
Investigators reviewed photographic and digital evidence in addition to text messages and other records of electronic communications, the statement said. Goodell issued the 6-game suspension after receiving a recommendation from a four-person external advisory panel.
Ian Rapoport of NFL Network says in a letter to Elliott, NFL executive Todd Jones said there was "substantial and persuasive evidence" referring to multiple violent incidents. Six games has been the league's standard for a domestic violence punishment. Immediately after it was announced, many speculated if Elliott would appeal it. Elliott has three days to file an appeal.
Elliott is eligible to participate in all preseason practices and games.
Without an appeal, the suspension would begin September 2 and he would be eligible to return to the active roster October 23, the day after the Cowboys' Week 7 game against the San Francisco 49ers.