The 29-year-old has joined Hull City on a season-long loan and will be eligible to make his debut when the Tigers face Ipswich Town at the KCOM Stadium after the international break, as he is unable to play against his parent club this weekend.
Martin has been with the Rams since 2013, scoring 64 times in 186 appearances, whilst also having loan spells with Fulham and Reading in the last couple of seasons. The Scotland international began his career with Norwich City and has since made more than 400 senior appearances.
Speaking after signing, Martin said: “I can’t wait to get started here after having a really positive chat with the Head Coach.
“Hopefully I can come here, play regular football and contribute towards helping the team to move up the table. I’m fit, fresh and ready to play as many games as possible.”