Its $40m (£32.4m) nudges it ahead of 2009’s Inglourious Basterds’ $38m (£31m) debut and Django Unchained’s $30m (£24.3m) opening in 2012.
The Lion King retained top position with $75.5m (£61m) in its second week.
The photo-realistic re-versioning of the 1994 Disney classic, starring a vocal cast which includes Beyonce, Donald Glover and British actor Chiwetel Ejiofor, has now taken $350m (£284m) at the North America box office and $963m (£780m) globally.
Tarantino’s movie outperformed expectations of $30m in takings, despite a more audience restrictive R-rating.
It scored an opening day record for the director, taking $16.8m (£14m) on Friday.
Once Upon A Time in Hollywood has an 85 rating on Metacritic and has been largely well-received by critics.
Time magazine described the film as “one of Tarantino’s best”.
It is Tarantino’s first made outside of the Weinstein Company or its predecessor Miramax and is one of his most expensive films to make, costing a reported $90m.
It follows DiCaprio and Pitt as an ageing actor and his long-time stunt double. Margot Robbie stars as Sharon Tate.
Tarantino’s Django Unchained is still – to date – his highest grossing film internationally.