The former Tottenham coach pulled out of the running due to "family reasons" at the end of March but on Tuesday moved to Meadow Lane on a three-year deal.
The 50-year-old Dutchman has six games to save his new side from relegation into Sky Bet League Two, with the Magpies currently one point from safety.
Notts County have been without a permanent manager since the departure of Shaun Derry on March 23, with Paul Hart and Mick Halsall taking caretaker charge of their recent games.
But Moniz, who steered Red Bull Salzburg to Austrian league and cup glory in the 2011/12 campaign, will now take the reins.
The club have confirmed that Dave Kevan will be Moniz's assistant, with strength and conditioning coach Mike Edwards and goalkeeping coach Kevin Pilkington remaining in their posts.
Magpies chairman Ray Trew told the club's official website: "As I have said previously, I set out on our search for a new manager with an open mind but with a determination to find someone who would be able to bring a new level of excitement to Notts County
"I think in Ricardo we have found that because, having spoken to him at length, his footballing philosophy is one of structured attacking play, which I hope is something that our fans will buy into, because I know that when I come to Meadow Lane I want to be entertained, I want to be excited by what I see out there on the pitch.
"Results, of course, are the yardstick by which managers are ultimately judged, but if we can play the sort of football that gets people off their seats and instil in our players the desire to take games to our opponents, I think we can make a real impression in this division.
"Ricardo has a fantastic reputation within the game, not only for the style of football that he plays, but also his ability to spot and nurture young talent, so I am confident that his appointment will be of benefit to all levels of the club.
"In Dave I have been able to bring in someone who knows this level of football and, perhaps equally importantly, knows this football club
He's a Notts County person and I am delighted that he agreed to return for what I feel is an exciting period ahead for the club.
"The new management team's immediate goal is clear, with survival in League One our short-term aim obviously, but work is already under way to ensure that we have the best possible squad available to make a real impression next season."
Source : PA
Source: PA