The move is set to be ratified on Friday and Easter will go straight into Kenny Jackett's side for Saturday's derby with Charlton at The Valley.
The 31-year-old has played for the Lions before, scoring on his debut against Swindon after securing a loan move to The Den in 2008.
Easter has scored twice in 11 appearances for Palace this season but will now turn his attentions to helping Millwall pull clear of the Championship relegation zone.







