The move ramps up efforts by Facebook to filter content amid growing criticism of the social media giant for allowing the platform to be used to promote violence and hateful activity.
"If we're going to build a safe community, we need to respond quickly," chief executive Mark Zuckerberg said on his Facebook page.
Zuckerberg's announcement came a week after a 20-year-old Thai man broadcast live video on the world's most popular social media platform, showing him killing his baby daughter before committing suicide.
The previous week, a US man dubbed the "Facebook Killer" shot himself to death after three days of a frantic nationwide manhunt.
The murder and a video sparked outrage across the world and renewed scrutiny of the growing number of grisly videos being posted on social media.
Facebook removed the footage hours after the attack. Zuckerberg acknowledged that the world's largest social network had a role to play in stemming the worrisome trend.
"We're working to make these videos easier to report so we can take the right action sooner -- whether that's responding quickly when someone needs help or taking a post down," Zuckerberg said.
The 3,000 new recruits, added over the coming year, will increase by two thirds the size of Facebook's community operations team, which currently numbers 4,500.
- 'We can do better' -
"We've seen people hurting themselves and others on Facebook (Swiss: FB-USD.SW - news) -- either live or in video posted later," Zuckerberg said. "It's heartbreaking, and I've been reflecting on how we can do better for our community."
The additional reviewers will "help us get better at removing things we don't allow on Facebook like hate speech and child exploitation," he said.
"And we'll keep working with local community groups and law enforcement who are in the best position to help someone if they need it -- either because they're about to harm themselves, or because they're in danger from someone else."
Critics say the social network has been too slow to react to online violence, and questioned whether Facebook Live -- a strategic area of development for the company -- should be disabled, after several cases in which it was used to broadcast rapes.
Zuckerberg said Facebook has been working on better technology that can identify violent or inappropriate content -- and that its efforts to screen for acts of violence appeared to be paying off.
"Just last week, we got a report that someone on Live was considering suicide," he said.
"We immediately reached out to law enforcement, and they were able to prevent him from hurting himself. In other cases, we weren't so fortunate."
It was not immediately clear how and where Facebook would deploy the new monitors.
As Facebook approaches a global user base of two billion, it has been grappling with its role as a platform for sharing news as well as calls to violence and political propaganda.
The company has insisted it is not a "media company" that manages content seen by users, but it has faced growing calls to weed out "fake news" that may influence elections as well as "hate speech" barred in some European countries.
Last month, Facebook stepped up its security to counter efforts by governments and others to spread misinformation or manipulate discussions for political reasons.
Facebook also recently unleashed a new weapon in the war against "revenge porn" at the leading social network as well as the messaging services Messenger and Instagram.