The winger has made nine starts for Martin Hunter’s Under-21s so far this season, scoring four goals in total.
20-year-old McQueen made his Saints debut in the FA Cup in February 2014, coming off the bench in the 1-0 defeat to Sunderland at the Stadium of Light.
The loan spell will be the first of McQueen’s career, having been a regular for Hunter’s development side over the last three seasons.
Southend currently sit ninth in League 1, with McQueen in line to make his debut when Phil Brown’s side take on Coventry City at Roots Hall on Saturday.
Young goalkeeper Harry Isted, who has made four under-21 appearances this season, has left the club by mutual consent.