Haynes-Brown joins Dons on loan
The defender, 23, will go straight into the Dons squad for Saturday's League Two trip to Bradford.
Haynes-Brown started his career at Colchester and has progressed back up the footballing ladder after spells in non-league football at AFC Sudbury and Lowestoft.
Wimbledon first-team coach Simon Bassey told the club's official website: "Curtis is a tall, powerful left-back, who can also play centre-back.
"He is a young lad who I am sure will boost our squad during his loan spell with us."