Michael Sheen is set to star in a Welsh comedy film about a UFO sighting – after sharing his own encounter with “a phalanx of lights” in his hometown.

Out There celebrates the “secret extraterrestrial history” of west Wales through the tale of a rebellious 16-year-old astronomy enthusiast who spots a UFO over her sleepy seaside town and ropes in her sceptical best friend and an eccentric ufologist – played by Sheen – to uncover the truth.

It will premiere at Edinburgh Film Festival In August, and features a host of Welsh actors.

Sheen has previously spoken about a series of spooky experiences in Port Talbot, south Wales, which convinced him the town was “very UFO-y”.

When Sheen returned to the area with his family in 1977, having lived for a while in Liverpool, he was told that his neighbour had seen “a UFO hovering over her back garden”.

“I got told this, at the age of eight, about this woman who lived next door who was clearly very sensible, so I totally believed this,” he told the Scarred For Life podcast, external in 2025.

Then, at 12 years old, after getting off the school bus, he recalled seeing “something coming round the edge of the mountain, in the distance”.

“I stopped, and this light came out and then two lights behind it, and then three lights behind. A sort of phalanx of lights coming from behind the mountain and floating out over the sea,” he said.

“As I’m standing there, I’m thinking, those are UFOs. I’m fairly certain those are UFOs.

“But I knew if I went in [to the house], they might disappear, so I just stood there transfixed and I watched them come all out, all over the ocean, and then they stopped, and then they all disappeared.

“No-one believed me, obviously.

“I have since heard that other people have seen things in Port Talbot, so I think there’s some sort of thing going on there.”

Out There is the debut feature film from director Simon Ryninks, who said the film “couldn’t ever be set anywhere else” but Wales.

“After my mum passed away, I found myself returning frequently to west Wales, where our family is from,” he told BBC Wales.

“I wanted to set something in that landscape as a way of reconnecting with her and to write about grief with humour and a lightness of touch.”

It is produced by Tibo Travers of Sweetdoh Films and Katie Dolan of Bad Cat and stars Welsh actor Nerys Amber Stocks as main character Maz, who becomes convinced that the mysterious UFO sighting holds the key to her father’s disappearance.

Ryninks added that learning about UFO sightings in west Wales in the 1970s also inspired the project.

“I loved the idea that this quiet, unassuming place had this secret extraterrestrial history and suddenly a landscape that felt deeply personal also had this strange cosmic grandeur and an innate sense of people longing for the unknown,” he said.

“I think there’s a particular openness in Welsh culture to mystery, magic and folklore, and the film sort of became a joyous celebration of that in a lot of ways.”

Ryninks said he had “always wanted to set a film on the Ceredigion coast as it’s my favourite place in the world”.

“For practical reasons, our main shoot took place around Bridgend, Nelson and Porthcawl, closer to where most of our cast and crew are based – and offered brilliant locations.

“But we also did some filming in Ceredigion, and that was when the film really began to feel like the one I’d carried in my head for seven years,” he said.

Typical unreliable Welsh weather was a major challenge for the cast and crew, who shot the film in October.

“We became convinced we were going to be completely rained off and were obsessively checking multiple weather apps and choosing whichever forecast frightened us least,” said Ryninks.

“Every day of pre-production it rained… then, when we started shooting, it barely rained at all, which felt miraculous.

“It was unseasonably dry, so I can only assume we have the aliens and their advanced weather-control technology to thank for that.”

The feel-good film about belief, finding meaning and coming to terms with loss also stars an array of other Welsh actors, including Tom Moya as co-lead, as well as Dunkirk’s Aneurin Barnard and Game of Thrones star Iwan Rheon.

“It was very important to me that the casting felt authentic,” said Ryninks.

He added the casting directors “worked tirelessly to bring an exciting ensemble together that was almost entirely Welsh”.

He admitted that Sheen’s character, Shifty Gruff, was written with him in mind.

“It was a total long shot, but, like a UFO believer, I held on to the possibility of making contact,” he said.

“To have all these actors in my debut feature was out of this world.”