Rhys Owain Evans (Welsh pronunciation: [r̥ɨːs ˈivans]; born 22 July 1967), known as Rhys Ifans, is a Welsh actor. He has portrayed roles in Twin Town (1997), Dancing at Lughnasa (1998), Notting Hill (1999), Kevin & Perry Go Large (2000), Enduring Love (2004), and The Boat That Rocked (2009), in addition to Xenophilius Lovegood in Harry Potter and the Deathly Hallows – Part 1 (2010), Dr. Curt Connors / Lizard in The Amazing Spider-Man (2012) and Spider-Man: No Way Home (2021), and Grigori Rasputin in The King's Man (2021). His television roles include Hector DeJean in the Epix thriller series Berlin Station, Mycroft Holmes in the CBS series Elementary, and Otto Hightower in the HBO fantasy series House of the Dragon.

Ifans was also formerly the frontman of the rock bands The Peth and Super Furry Animals.

Ifans was born Rhys Owain Evans in Haverfordwest on 22 July 1967, the son of nursery school teacher Beti-Wyn (née Davies) and primary school teacher Eirwyn Evans. His younger brother, Llŷr Ifans, is also an actor. He grew up in Ruthin, where he received his primary education at Ysgol Pentrecelyn and was raised speaking Welsh as his first language. He attended Ysgol Maes Garmon, a Welsh medium secondary school in Mold, where he took his O levels and A levels. He attended acting classes at Theatr Clwyd. After leaving school, he presented Welsh-language television programmes on S4C. He studied acting at the Guildhall School of Music and Drama in London, where he graduated in 1997.

Ifans' early stage work included Hamlet at Theatr Clwyd, A Midsummer Night's Dream at the Regent's Park Theatre, and Under Milk Wood and Volpone at the National Theatre. He appeared at the Donmar Warehouse in 2003's Accidental Death of an Anarchist. In 2006, he returned to the London stage in Michael Grandage's production of Don Juan in Soho at the Donmar Warehouse. In 2016, Ifans played Fool alongside Glenda Jackson in Deborah Warner's production of King Lear, at The Old Vic. He returned to The Old Vic to play Ebenezer Scrooge in Matthew Warchus' production of A Christmas Carol (adapted by Jack Thorne) in 2017 and in 2018 returned to the National Theatre to play King Berenger in Patrick Marber's new adaptation of Eugene Ionesco's Exit the King. Ifans was given the role of Atticus Finch in Aaron Sorkin's To Kill A Mockingbird to begin at London's Gielgud Theatre on 21 May 2020. The play was delayed due to the COVID-19 pandemic but was rescheduled for May 2021. The role of Atticus Finch was later given to Rafe Spall due to scheduling conflicts.

Ifans appeared in many Welsh-language television programmes before embarking on his film career, including the comedy show Pobol y Chyff [cy], as well as performing at the National Theatre, London and the Royal Exchange, Manchester. In 1990, he presented Stwnsh (Welsh for "Mash"), an anarchic children's quiz programme; 31 fifteen-minute programmes were broadcast on Welsh-language TV channel S4C.

In 2000, he narrated the children's animated series Sali Mali for S4C. In 2004, his performance as Peter Cook in the TV film Not Only But Always won him the BAFTA Best Actor at the 2005 British Academy Television Awards.

In 2005, Ifans made a guest appearance for the rock band Oasis in the video for their single "The Importance of Being Idle" (where he mimed to Noel Gallagher's vocals), for which he accepted their award for Video of the Year at the 2006 NME Awards. He has also appeared in the music videos for "God! Show Me Magic" and "Hometown Unicorn" by Super Furry Animals, "Mulder and Scully" by Catatonia, and "Mama Told Me Not to Come" by Tom Jones with Stereophonics.

In 2008, he appeared in "Six Days One June", one of three episodes of the TV series The Last Word Monologues, written by Hugo Blick and broadcast on BBC Two. He played a lonely Welsh farmer trying to free himself from a domineering mother.