Katherine Heigl’s career has long been shaped by sharp pivots and unmistakable screen presence, beginning with early television work that quickly gave way to roles carrying both commercial pull and emotional weight.
From breakout turns in romantic comedies to her acclaimed stretch on Grey’s Anatomy, she built a résumé defined less by a single signature character and more by a string of performances that reflected her instinct for timing, charisma and controlled vulnerability.
As she turns 46, the milestones of her film and television work take on renewed clarity. Certain roles, whether in drama, comedy or those hybrid spaces in between, rise above the rest for the imprint they left on audiences and on the projects surrounding them.
Dr. Isobel “Izzie” Stevens | Grey’s Anatomy
Izzie Stevens was not merely a role; it was a cultural phenomenon that cemented Heigl’s status as a drama powerhouse. Her five-year tenure on the groundbreaking medical series was defined by a soaring arc that took the former model from a naive, insecure intern to a doctor hardened by impossible choices.
The narrative high points—from the wrenching drama surrounding her patient Denny Duquette to her personal battle with cancer—demanded a profound emotional range. Heigl’s work here, which culminated in a deserved Emmy win for Best Supporting Actress, skillfully captured the messy, passionate, and often heartbreaking reality of life inside the high-stakes corridors of a teaching hospital.
Tullulah “Tully” Hart | Firefly Lane
Marking a significant return to serialized television, Tully Hart offered Heigl one of her most complex and nuanced dramatic canvases. Over two seasons, she masterfully portrayed the celebrated talk-show host across multiple decades, from her ambitious, reckless youth to her complicated, highly successful adulthood.
The role required Heigl to constantly navigate the heavy baggage of childhood trauma and the demands of a tumultuous, codependent friendship. It was a raw, deeply felt performance that provided a mature and compelling exploration of female ambition and the lifelong sacrifices made in the name of career and connection.
Samantha Wheeler | Suits
Heigl’s late entry into the established world of Suits was a calculated, electric shift in her career trajectory. As the highly assertive, ruthlessly efficient attorney Samantha Wheeler, she shed the romantic comedy persona entirely, embracing a more hardened, unapologetically powerful character.
Samantha was a force of nature, instantly commanding respect—and fear—in the high-powered legal drama. Heigl’s sharp, confident performance gave the show a jolt of energy and proved her capability to inhabit characters whose primary motivations are professional dominance and strategic brilliance, further diversifying her dramatic portfolio.
Isabel Evans | Roswell
In one of her foundational roles, Isabel Evans grounded the late-90s teen sci-fi boom with a relatable sense of otherness. As one of the alien protagonists trying to pass as human in a small desert town, Heigl perfectly encapsulated the poignant alienation of adolescence intensified by an existential secret.
Her performance captured the perpetual tension between Isabel’s duty to her alien heritage and her desperate, deep-seated desire for a normal teenage existence, making her a fan favorite and an early indicator of her ability to handle complex emotional duality.
Alison Scott | Knocked Up
This was the film that launched Heigl into the A-list stratosphere and solidified her ability to anchor a massive commercial hit. As Alison, the highly ambitious entertainment journalist who falls pregnant after a one-night stand, Heigl provided the indispensable, grounded reality needed to balance Judd Apatow’s signature raunchy humor.
Her performance was a masterclass in the comedic foil—smart, organized, and increasingly exasperated—giving the film its emotional core and ensuring that the audience invested in the unlikely, messy journey toward accidental parenthood.
Jane Nichols | 27 Dresses
27 Dresses is arguably the definitive role of her romantic comedy era, a character that became a cinematic archetype. Heigl’s Jane was the perpetual bridesmaid—a woman flawlessly organized and emotionally available for everyone else’s life, but utterly paralyzed in her own romantic pursuits.
The performance perfectly captured the charm and frustration of a woman sacrificing her own happiness out of obligation. It was a warm, engaging, and highly marketable portrayal that showcased her sharp, relatable appeal in a genre she dominated for years.
Abby Richter | The Ugly Truth
Heigl dove headfirst into the high-concept, rapid-fire dialogue of this battle-of-the-sexes comedy. As Abby Richter, the meticulously controlled, romance-obsessed morning show producer, she delivered a performance of electric, high-strung energy.
Her success here was built on the palpable, combative chemistry she generated with her co-star, making the transformation from rigid skeptic to open romantic believable and hilarious. The film highlighted her knack for delivering snappy dialogue and selling the physical comedy of emotional chaos.
Holly Berenson | Life as We Know It
This role found Heigl balancing the expected tropes of the romantic comedy with the profound, touching drama of instant, accidental parenthood. As a successful baker forced into co-parenting an orphaned baby with a man she dislikes, Holly was a character who had to mature rapidly.
Heigl’s performance was praised for its sincerity and for convincingly conveying the exhausting, immediate love that develops through shared responsibility, giving the film an emotional anchor far deeper than its surface premise suggested.
Tessa Connover | Unforgettable
Heigl made a notable, conscious departure from her established brand with this psychological thriller. Her portrayal of Tessa, the manipulative, obsessed ex-wife determined to destroy her ex-husband’s new relationship, was a deliberate and effective turn toward playing a complex antagonist.
It was an icy, controlled performance, full of menacing intensity, demonstrating her capability to deliver tension and chills, and proving she could embody calculated villainy with conviction.
Sarah Ryback | Under Siege 2: Dark Territory
This early action role showcased a teenaged Heigl handling high-stakes physical drama with remarkable composure. Cast opposite Steven Seagal on a runaway train, her character, Sarah Ryback, served as the primary emotional motivation for the hero while still being an active participant in the chaos.
The performance remains a fascinating piece of her early filmography, indicating her inherent screen presence and ability to navigate a major blockbuster environment years before her medical drama stardom.