The 36-year-old never thought he would get the chance to play competitive cricket again, having last done so almost five years ago, but has been training with Lancashire in recent months and is now relishing his opportunity to return.
"I'm really honoured to be part of Lancashire once again," he said on www.lccc.co.uk. "It is something that I never thought would happen but, after training with the squad over the last few months, I am really happy that they have invited me to play.
"I have worked really hard to get back to my fittest and I hope that we have a successful summer. I'm just glad that I can be part of it."
In confirming Flintoff's return, Lancashire did not specify when he was likely to be back in action to boost Glen Chapple's men in their bid to reach finals day at Edgbaston in August.
The Lightning are in T20 Blast action at Old Trafford on Friday evening when they take on Birmingham Bears, before hosting Roses rivals Yorkshire Vikings next Friday.
LCCC cricket director Mike Watkinson said on www.lccc.co.uk: "We are delighted to have Fred involved once again at the club. He is Lancashire through and through and his record for both club and country speaks for itself.
"Fred has been back at Emirates Old Trafford under his own steam since the winter and has been working with the academy and in the nets with some of the other players.
"Over a period of time he has picked up on his physical conditioning and this continues to improve. He has shown in practice that he still has plenty of class with bat and ball, and will be a great addition to the NatWest T20 Blast squad."
There was speculation Flintoff might return for Lancashire 2nd XI in a friendly against a representative team from the North Staffordshire and South Cheshire League at Leek on Tuesday.
Instead, he appeared at Headingley to join training with the first-team squad before day three of their LV= County Championship match against Yorkshire.
In his years away from cricket, Flintoff has explored other options - including one bout of professional boxing.
He represented England in 79 Tests, 141 one-day internationals and seven Twenty20 games. He also made 80 first-class appearances for the Red Rose, scoring 4,042 runs at 35.14 and taking 92 wickets at 29.16.
Flintoff's Lancashire Twenty20 record consists of 16 games, averaging 13.94 with the ball and 29.64 with the bat, with a high score of 93 against Derbyshire in 2009.
- Sports & Recreation