Domhnall Gleeson on Taylor Swift, a Five-Month Perm and Three New Releases

Domhnall Gleeson is, by his own admission, slightly mortified. Someone — possibly his The Incomer co-star Gayle Rankin — recently joked that this was the "summer of Domhnall", a reference to the unusual density of his forthcoming releases. The phrase has since proliferated across the internet, which Gleeson finds uncomfortable. "The worry is that somebody will say this to me now thinking that I believe it," he told The Guardian during an interview at a London hotel.

The label captures something real. Within a matter of weeks, three projects are landing simultaneously: The Incomer, an eccentric Scottish comedy written and directed by Louis Paxton and filmed at the northern tip of Scotland; The Paper, the second season of a US mockumentary about a struggling Ohio newspaper; and Bucking Fastard, a new film from Werner Herzog that is due to screen at the Venice film festival. The Paper launches on Sky and NOW in the UK on 10 September, while The Incomer reaches UK cinemas from 4 September.

Preceding all three was his appearance in Taylor Swift's music video for Opalite, directed by Swift herself, in which Gleeson plays a lonely man who is magically matched with Swift and the pair dance together in matching glittery turquoise tracksuits. The project originated, improbably, from a joint appearance on the Graham Norton show last October. Gleeson joked on air that he hoped to appear in a Swift music video; a fortnight later, he says, an email arrived. Swift had invited every other guest that evening — Cillian Murphy, Greta Lee, Jodie Turner-Smith, Lewis Capaldi, and Norton himself — to take part. "No one else in the world can come up with an idea like that and make it happen," Gleeson said. He was informed the evening before filming that there would be a dance sequence. "I was like, are you fucking joking?" He spent the night practising in front of a mirror. Swift's direction resolved matters: she told him "full send" and urged him simply to experience the joy of it. The first take after that instruction was the one used.

In The Incomer, Gleeson plays a mainland bureaucrat dispatched to a remote Scottish island to evict its only residents, a pair of insular siblings played by Rankin and Grant O'Rourke. To achieve what he describes as a "comedic silhouette" — a lollipop-shaped head — he had a perm, which he then lived with for four or five months after filming wrapped. "No one talks about the dedication of an actor any more," he said, with evident enjoyment of the absurdity.

His character in The Paper is a more conventionally groomed figure: an idealistic editor at a once-prestigious Ohio newspaper, now an afterthought to the parent company's core toilet-paper manufacturing business. The show, a gentle mockumentary in the tradition of co-creator Greg Daniels's earlier work, touches on the wider decline of local journalism. Gleeson spent months before production shadowing journalists at Ohio's surviving daily papers, attending editorial meetings and asking questions. By the time the first season reached its press cycle, he said, one journalist he had shadowed had already left the profession — unable to make a living. "It's harder than it should be to do good journalism," he observed. "People don't want to pay for it, and people who it's against don't want it to exist."

In Bucking Fastard, Herzog's film based on the true story of twins Freda and Greta Chaplin — the title being a spoonerism both women made simultaneously in court — Gleeson plays a social worker. He worked only a few days on the production but found the experience memorable, not least because he came to suspect his character was partly modelled on Herzog himself. He declined, emphatically, to attempt Herzog's accent. "For a second in your mind you're like, 'Should I do it?' Then you're like, 'No. Absolutely not.'"

Now 43, Gleeson has accumulated credits ranging from General Hux in the Star Wars sequels to Bob Geldof, AA Milne, and Bill Weasley in the Harry Potter films. He attributes his adaptability in part to a deliberate avoidance of type, and in part to an early career rooted in theatre. He received a Tony nomination for Martin McDonagh's The Lieutenant of Inishmore, which transferred from London to Broadway. He has since worked repeatedly alongside his father, Brendan Gleeson, and his brother Brian — in McDonagh's Oscar-winning short Six Shooter, in the Harry Potter films, and in Darren Aronofsky's Mother!, among others.

He remains deliberately absent from social media and reluctant to discuss his personal life, describing the decision as "a line in the sand that helps immediately in terms of the personal not being public". Whether the summer belongs to him or not, Gleeson appears content with the uncertainty of what comes next. "You don't know what the next job is going to be, you don't know what the next challenge is going to be," he said. "It's where I'm happiest."