Left-back moves to The Den in deal until the end of the seasonMillwall have signed Nottingham Forest left-back Dan Harding on loan until the end of the 2014/15 season.
Dan, who has just turned 31, becomes Ian Holloway's second signing of the January transfer window following last week's arrival of winger Paris Cowan-Hall from Wycombe Wanderers.
Vastly experienced at Championship level, Dan's career began at Brighton & Hove Albion, where he made 76 appearances between 2002 and 2005.
He then joined Leeds for a six-figure fee but moved on to Ipswich Town just one year later, playing 73 League games at Portman Road across three seasons.
During his time in Suffolk Dan enjoyed loan spells with Southend and Reading, but his next permanent move was to Southampton, who brought the defender to St Mary's in 2009. Dan was a near ever-present for Saints in his three-year spell, making 121 appearances in total before joining Nottingham Forest in July 2012.
The former England U21 international trained with his new team-mates for the first time this morning and could be in line to make his Lions debut in Saturday's game at Blackpool.