Milanic was recruited from Austrian side Sturm Graz on a two-year deal last month to replace Dave Hockaday, who was sacked by Leeds owner Massimo Cellino on August 28 after six games in the hotseat.
However, the Slovenian has now suffered the same fate having failed to register a single victory during his six games in charge.
The final game of Milanic's tenure resulted in a 2-1 defeat at home to Wolves on Saturday, with James Henry and Leon Clarke conspiring to ensure three points for the visitors and leave Leeds in 18th.
"I want to apologise to the supporters, they deserve better results," said Cellino.
Long-serving academy coach Neil Redfearn will take charge of first-team training on Monday with the 49-year-old having regularly assumed control in the past.
During his most recent spell at the helm, Leeds took nine points from a possible 12.
Cellino had previously stated his desire to ensure Redfearn remains in charge of the club's academy, but seemingly turned on that as he told Sky Sports News: "Neil Redfearn will take training on Monday. He is the new head coach, 100 per cent."