Noor Salman was taken into custody in San Francisco, facing charges of aiding and abetting, as well as obstruction of justice in the case of the worst mass shooting in American history, said a CBS News report.
Federal Bureau of Investigation agents took Salman Mateen into custody at a home in Northern California, authorities said.
Mateen was killed in a shoot-out with police after carrying out the deadliest mass shooting in modern USA history at a gay nightclub in Orlando last June.
Salman's first court appearance is scheduled for Tuesday.
The FBI has come to the conclusion that the wife of Orlando nightclub shooter Omar Mateen isn't quite as innocent in the attack as she claims. "I am very sorry for what has happened".
Factory output rises in November despite demonetisation
Meanwhile, the industrial production grew by 5.7 per cent in November against contraction of 3.4 per cent same month past year . Capital goods production increased by 15 per cent in November compared to a decline in production by 24.4 per cent earlier.
According to law enforcement officials, Mateen also texted with his wife during the shooting, which has helped lead to the increase of scrutiny from the Federal Bureau of Investigation. The Tampa Bay Times reports that she filed a petition in California court last month to change the name of her son by Mateen. "He has hurt a lot of people", she said.
Salman told media in November that Mateen abused her during their five-year marriage, even while she was pregnant. After swapping texts, she tried to call him.
Mateen, the perpetrator of the deadliest mass shooting in U.S. history, was killed inside the club after a standoff of several hours. In some cases, she also said that didn't know everything or what her husband was planning that night. She had moved to Contra Costa County after the shooting.
It was unclear when Mateen married Noor Salman, his second wife. The messages seemed to show that Mateen had not told his wife what he was up to and after he declared that "I love you, babe", he stopped responding to her attempts to make contact.