Kat Jeffery is a Canadian costume ager, dyer, and designer with over a decade of experience across film, television, theatre, opera, and dance. She holds an MFA in Costume Design from NYU Tisch School of the Arts and a BFA in Theatre Design from the University of Victoria.

Her process is rooted in research, precision, and hands-on experimentation. Whether hand-dyeing fabric to evoke a post-apocalyptic palette or aging a costume to convey years of hardship in a single glance, Kat’s work is ultimately about character—using fiber, dye, and texture as tools to build identity and history. With a background in costume design, she approaches aging and breakdown with a keen understanding of how material choices support and enhance the narrative.

Now based in her hometown of Calgary, Alberta, Kat’s recent screen credits include Die My Love (2025), Billy the Kid S2 & S3 (Paramount+), Fargo S5 (FX), and The Last of Us S1 (HBO). She has worked extensively across Canada and the U.S., with experience on both studio and location-based productions. Her time at Vancouver’s Lovett Studios contributed to numerous high-volume series and feature films. Earlier in her career, she designed and illustrated costumes for theatre, opera, and virtual reality projects in New York City.

When not on set, Kat maintains an active studio practice in painting and is deeply engaged in researching sustainable, natural dye methods tailored to the pace and demands of professional costume production.