Happy Birthday: Kyle Merritt MacLachlan (né McLachlan, February 22, 1959) is an American actor best known for his Emmy-nominated and Golden Globe-winning role as Dale Cooper in Twin Peaks (1990–1991, 2017) and its film prequel Twin Peaks: Fire Walk with Me (1992). He is also known for his roles in another two of Twin Peaks co-creator David Lynch's films: Paul Atreides in Dune (1984) and Jeffrey Beaumont in Blue Velvet (1986). MacLachlan's other film roles include Lloyd Gallagher in The Hidden (1987), Ray Manzarek in The Doors (1991), Cliff Vandercave in The Flintstones (1994), Zack Carey in Showgirls (1995), and Riley's father in the Inside Out film series (2015, 2024).

In addition to Twin Peaks, MacLachlan has had prominent roles on television such as Trey MacDougal on Sex and the City (2000–2002), Orson Hodge on Desperate Housewives (2006–2012), The Captain on How I Met Your Mother (2010–2014) and How I Met Your Father (2022), the Mayor of Portland on Portlandia (2011–2018), Calvin Johnson on Agents of S.H.I.E.L.D. (2014–2015), and Hank MacLean on Fallout (2024–present).

MacLachlan made his film debut in Dune (1984) in the starring role of Paul Atreides. MacLachlan was performing in Molière's Tartuffe at a Seattle-area theater when a casting agent for Dune producer Dino De Laurentiis began searching for a young lead and received multiple recommendations for him. After several screen tests, he hit it off with director David Lynch, aided by their common Pacific Northwest backgrounds, and succeeded in winning the part. This marked the beginning of a creative partnership between MacLachlan and Lynch, who would go on to collaborate on four more projects before Lynch's death in 2025.