Jesse Eisenberg has revealed he's donating a kidney to a total stranger.

The 42-year-old actor shared the surprising news during an appearance on Thursday's episode of the Today Show. As he discussed working with the show to set up a blood drive, Eisenberg explained he has now gone one step further in a bid to help others.

"I just have so much blood in me, and I feel like I should spill it," he joked. "I really like doing it, and I don't know why."

He added, "I'm actually donating my kidney in six weeks. I really am."

Eisenberg went on to explain that he has signed up for an altruistic donation, where a donor agrees to give an organ to a stranger. The person receiving the organ will be selected by medical compatibility.

The donation procedure will take place at the end of the year.

"I got, like, bitten by the blood donation bug. I love it," Eisenberg continued. "I'm doing an altruistic donation in mid-December."

During a separate interview with Today.com published on Thursday, the Hollywood star offered more information on how the process works.

"Let's say person X needs a kidney in Kansas City, and their child or whoever was going to donate to them is, for whatever set of reasons, not a match, but somehow I am," he shared.

"That person can still get my kidney, and hopefully that child of that person will still donate their kidney, right?"

Eisenberg added, "But it goes to a bank where that person can find a match recipient, but it only works if there is basically an altruistic donor."

Describing the process as "essentially risk-free" and "so needed", the Now You See Me star urged more people to consider following in his footsteps.

He insisted, "I think people will realise that it's a no-brainer, if you have the time and the inclination."