However, Saints coach Steve Wigley says Ormerod is still part of his long-term plans at St Mary's.
Wigley said: "Brett is going to join Leeds on loan for a month. He hasn't had enough football lately and Leeds, Brett and ourselves will benefit.
"He'll go until the end of the month and at the end of the month we will have him back hopefully with a few games and goals under his belt.
"It is just a case that we feel we will benefit in a few weeks and Brett will benefit straight away."
Kevin Blackwell has just three recognised strikers and they have only managed the one goal between them so far this season.
Former Middlesbrough strikers Michael Ricketts and Brian Deane have not scored and Julian Joachim has scored once with former Manchester United midfielder Danny Pugh the club's top scorer with five.
Ormerod hasn't appeared at all for Saints' first team since the opening day of the season. He wasn't even on the bench for last Monday's draw at Charlton, while teenagers Dexter Blackstock and Leon Best were preferred to him when the reserves visited The Valley two days later.
In all, Ormerod has scored 11 Premiership goals for Saints in 45 starts plus 27 as a sub since signing for £1.7m from Blackpool in December 2001.