Ambrose, who is 30, has joined Derby on a short-term contract which will run until the end of the 2018/19 campaign.
The Nigerian international centre-back joins the Rams as a free agent after he left Scottish Premiership side Hibernian last month.
Ambrose has been training with Derby’s first-team squad in recent days and will now provide another option for manager Frank Lampard to call upon in central defence.
As well as having over 50 international caps to his name, Ambrose won four Scottish Premiership titles during an impressive spell at Celtic – as well as the Scottish Cup and Scottish League Cup with the Glasgow giants.
He was also part of the Hibernian side which won the Scottish Championship title two seasons ago to return to the top flight of Scottish football.
Lampard said: “We’ve had the chance to take a look at Efe over the last few days and likewise he has been able to see how we work and want to play.
“Efe is an experienced central defender and he gives us another option in that particular area. We’re pleased to welcome him on board for the rest of the season.”
Ambrose’s playing career began in Nigeria with Kaduna United, while he also had a loan spell at Bayelsa United as part of his early development. He won the Nigerian Premier League with Bayelsa and the Nigerian FA Cup with Kaduna before linking up with Israeli outfit FC Ashdod in 2010.
Ambrose spent two years in Israel before he attracted interest from elsewhere and he eventually linked up with Scottish giants Celtic, managed by Neil Lennon, in August 2012 for an undisclosed fee.
The defender remained with Celtic until the summer of 2017 and enjoyed plenty of success over the course of 168 appearances, scoring six times.
He was a regular in his first four full seasons in Scotland and helped Celtic lift the Premiership title on each occasion – as well as the 2012/13 Scottish Cup and the 2013/14 Scottish League Cup.
During that time, he was also able to enjoy playing Champions League and Europa League football. His finest hour on the European stage came in November 2012 when he produced a superb display as Celtic defeated a star-studded Barcelona side 2-1 at Parkhead in the Champions League.
After failing to feature under new manager Brendan Rodgers, Ambrose featured less regularly during the 2016/17 campaign and he eventually moved out on loan to Hibernian in the Scottish Championship.
The move to Edinburgh saw him reunited with his former manager Lennon and he helped the Easter Road outfit seal promotion back to the top flight as Champions.
Out of contract in the summer of 2017, Ambrose penned a two-year deal with Hibernian and played 45 times in all competitions last term as they finished fourth in the table. He remained a regular this season, appearing 24 times, before a clause in his contract saw him move on as a free agent in January 2019.
In total, he made 81 appearances in during his time at Easter Road.
Ambrose has 51 caps for Nigeria, winning his first cap in 2008 and his last in 2016. He was an African Cup of Nations winner in 2013, where he was named in the Team of the Tournament, while he also claimed a Silver Medal in the 2008 Summer Olympics.