Back to the Future cast have an epic reunion nearly 40 years after the original film premiered

The Back to the Future cast has had an adorable reunion at a fan convention.

The sweet reunion was captured by Lea Thompson, who starred in the film as Lorraine Baines McFly, the mother of Michael J Fox's character Marty.

In the heartwarming image, Fox, 61, can be pictured sitting alongside Christopher Lloyd, 84, and Tom Wilson, 63.

Lloyd played the iconic Dr. Emmett 'Doc' Brown, while Wilson played bullies Biff Tannen, Griff Tannen, and Buford 'Mad Dog' Tannen.

Fox, Thompson, and Wilson have all grown up since the trilogy began in 1985, however Lloyd has barely changed at all in three decades, looking every bit like the character that fans grew to know and love.

Thompson captioned her post: "Wow, honestly had the best time today with my Back to the Future family. So many fun fan moments too and a llama."

A llama? Thompson doesn't give further details, but we're desperate to know more about the llama, who we can only assume is a time-travelling animal to fit with the Back to the Future vibes.

Of course, we're 99.99 per cent sure we're wrong, but it can't hurt to dream.

Thompson shared several moments from the day on social media.

She caught Lloyd on camera, teasing him as she went: "Look who's here. Look what the cat dragged in."

Lloyd can be seen grinning at her in the short clip, while in another video Thompson can be seen cuddling Wilson.

She went on to call him 'my favourite guy ever.'

Awww.

Fans lapped up the adorable snaps, with many taking to the comments section to thank the actors for bringing them the much-loved movie classics.

One fan said: "Nostalgia heart explosion emoji."

Another added: "My heart just burst from these pictures."

A third joked: "Biff doesn't look like old Biff from the future."

The sweet reunion came only months after Fox and Lloyd caught up in October at another fan convention.

At the October event, Fox walked out onto the stage, stopping for a moment to treat fans to an air guitar version of Marty McFly’s moves from the film's legendary ‘Johnny B. Goode’ scene.

After he was joined by Lloyd, the pair hugged it out before taking to the couch to respond to questions from fans.

The emotional reunion proved to be a bittersweet moment for fans, who were left in tears seeing the stars of the 1985 sci-fi favourite together again.