Kaitlin Olson's Stunning Transformation

It's no secret that the world of sitcoms is still a mostly male-dominated terrain, but in recent decades, more and more women have not only made us laugh in the popular series genre, but are also the sole reason we kept binging the projects. And one of those is undeniably Kaitlin Olson. Now, we're not undermining the rest of the cast on "It's Always Sunny in Philadelphia" (the men in the cast are also doing a remarkable job), but as Sweet Dee, Olson has won the sitcom numerous fans.

With over two decades spent gracing our small screens, Kaitlin Olson has undeniably become television royalty. Speaking to Harper's Bazaar in 2025, the actor revealed that she had always had her heart set on a career in Hollywood. "I wanted to be a TV star. My mom has notes that I wrote to her when I was in the second grade about how I wanted to be on television," she shared. "But I also wanted to be a veterinarian, a psychologist and a hairdresser — so I don't see any reason why I can't still do all of these things," Olson added. And frankly, we wouldn't be surprised if she explored other career paths, because if there's one thing Olson has shown over the years, it's that she is capable of it all!

Prior to 2005, Kaitlin Olson worked on projects like the film "Coyote Ugly" and the series "Curb Your Enthusiasm," but it wasn't until she got cast on the sitcom "It's Always Sunny in Philadelphia" that she caught everyone's attention. On the popular series, Olson was cast as Deandra "Sweet Dee" Reynolds, one of the project's main characters. With the gig, Olson's life changed completely.

In 2008, she opened up about her life prior to her big break. "I am from a little town outside of Portland, Oregon. Although, I spent the first eight years of my life on a little island across from Seattle, but basically I'm from the Pacific Northwest. I've been down here in Southern California for about 10 years and I definitely call this home," she shared (via HoboTrashCan). At the time of her breakthrough, Olson's style was very California laid-back. Loose and flowy dresses, boots, and long necklaces were a staple of her closet, as the actor navigated transitioning from her 20s into her 30s.

The second half of the 2000s was just as bold and quirky as the first half, and for Kaitlin Olson's style, this meant embracing maxi dresses whenever possible. The sitcom star adored rocking a floor-length piece — but not in a glamorous Hollywood manner. Instead, Olson rocked everyday maxi dresses to industry events, showcasing a more relaxed but nevertheless stunning approach to red-carpet fashion.

Speaking of her career, Olson acknowledged that "It's Always Sunny in Philadelphia" entirely changed her life. "Before then, I was just doing little things here and there, supporting by working multiple other jobs to be able to still audition, and every once in a while I'd get an acting job," she told Harper's Bazaar in 2025. "It changed my life so much for sure — that's how I met my husband." Olson met co-star Rob McElhenney on the set of the sitcom, and soon after, the two fell in love.

2008 marked a very important year for Kaitlin Olson's personal life as she tied the knot with her "It's Always Sunny in Philadelphia" co-star Rob McElhenney. In 2017, she revealed to Glamour that she knew pretty soon after they began dating that he was the one. "Once we really started dating, I knew that we would get married," she gushed. "That's so cheesy, but now that I've dated a bunch of people, then found him and gotten married, you really do know. You really do. So if you've got doubts and you're not sure, the answer is no, it's not right."

At the time, the actor discovered her fondness for black fashion, often attending events in black minidresses — sometimes even with leggings underneath. While skirts-over-pants is a mid-aughts trend we never thought we'd see again, we're happy that its recent resurgence didn't last for long. In fact, Olson herself only briefly explored the trend in the 2000s. In a 2008 interview, Olson revealed that if she weren't an actor, she would be a hairstylist or manicurist. "I really love it. I still really love it. I did all of my friends' acrylic nails for prom," she explained (via HoboTrashCan). "I taught myself how to do fake acrylic nails and I did all of them for prom." In the same conversation, the star shared her love for being sustainable. "I'm a little obsessive with recycling and eating organic food," she admitted. "I've kind of been forcing the issue on our set. Our set got pretty green this year. I'm thinking of incorporating compost into season five on set."

In 2010, Kaitlin Olson gave birth to the couple's first son, Axel Lee McElhenney, and in a conversation with Best for Babes before giving birth, she revealed that she had decided to welcome the baby at home. "I decided on a homebirth because I believe that as long as a pregnancy is normal and complication-free, your body knows what to do, and does not need medical intervention," Olson shared (via People). "I believe I'll be most relaxed and feel safest in my home, with an amazing nurse-midwife monitoring the baby and me the entire time, of course." While pregnant, Olson shot a season of "It's Always Sunny in Philadelphia," and her pregnancy was written into the storyline.

In a conversation with Healthy Mommy & Baby after giving birth, Olson admitted that regular exercise remained a priority of hers. "Even when I am tired I exercise and it revives my energy," she shared. "It is also important to plan time in your day to rest, especially if you are working. A balance of exercise and forced rest has been really good for me." In late 2011, Olson announced that she and her husband were expecting their second child. "We're having a boy! We're so happy that Axel gets to have a brother so close in age," she shared with People (via CBS News).

Style-wise, Kaitlin Olson kept it simple in the early 2010s with neutral colors being her go-to palette. The actor stuck to what she felt comfortable in, and her hair and makeup were usually done in a consistent way. Simple looks became her staple, as Olson rarely overaccessorized her red-carpet fashion. In fact, mastering minimalist dressing became something Olson was known for.

In 2012, Kaitlin Olson gave birth to her and Rob McElhenney's second son. "Leo Grey McElhenney... born April 5th after 23 very very long hours. We're in love," Olson wrote on X at the time. Olson and McElhenney focused on their family life, and their children would accompany them to events when appropriate.

As a mother of two, Olson prioritized what mattered to her the most, and fashion certainly wasn't at the top of the list then. Simple dresses and comfortable clothing became an even more prominent choice of hers. Now, don't get us wrong — the "It's Always Sunny in Philadelphia" star always looked gorgeous, and her happiness was contagious. In fact, looking back, it certainly seems as if the actor enthusiastically embraced the Scandi fashion style that you don't have to compromise comfort for, and it looked incredible on her!

As the mid-2010s were approaching, Kaitlin Olson started exploring fashion more intensively again. Still focusing on her work and motherhood, the actor occasionally attended an industry event, and it was there that she would show off how up to date with trends she was. Olson was still embracing a minimalist approach to clothing, but that didn't mean her looks couldn't be fun.

In fact, in 2015, the "Finding Dory" star attended the annual GO Campaign Gala in Beverly Hills, California, and for the event, she went with one of the biggest trends of the period — skinny leather pants. While the trend isn't nearly as popular as it was (and it has been replaced by wider silhouettes), we can all definitely learn from Olson how to stop being intimidated by leather pants and style them like a pro.

In 2017, Kaitlin Olson opened up to Glamour about a cycling accident she had at the age of 12, which gave her a fractured skull. "I still have a hole in my head. It was the size of a lime. Now it's the size of a quarter," she shared. "It was bad." Olson revealed that having to have a big scar, swelling, and a shaved head didn't help her confidence in school, but luckily, the star overcame all of it. And today, she's much stronger because of what she went through.

The actor also admitted that motherhood taught her how to be more relaxed. "I'm also a bit of a perfectionist, so trying to do 100 things perfectly well is completely impossible," she explained. "The thing I've learned is that it's so important to stay in the moment and not let my brain [think too far ahead]." Even though she rarely talked about fashion in her interviews during this time, Olson did share a piece of advice with Good Housekeeping. "Figure out what you do the most in your day, then put your money toward those kinds of clothes," the sitcom star said. "If I'm spending a big part of my day driving my kids to and from preschool, I'll buy loungewear or workout clothes that I feel good in." For industry events, Olson continued going for simple and elegant fashion, but we noticed that colors started slowly infusing her wardrobe.

While Kaitlin Olson was always known for simple silhouettes and neutral colors, as the end of the 2010s was approaching, a shift in the actor's fashion choices became noticeable. Now, Olson was embracing subtle patterns and unexpected colors like blue and green. In her early 40s, Olson was clearly in a more confident place to have fun with her look, and that included makeup and hair. Occasionally, she'd give us an unexpected side braid or the perfect red lip. In fact, we are in awe at how Olson perfectly picked the best lipstick color for her lip shape.

As the decade was approaching its end, Olson reflected on the show that made her famous, sharing her love for the work everyone was still putting into "It's Always Sunny in Philadelphia." "I'm legitimately impressed every season when I read the episodes," she told Uproxx in 2018. "That they're all so funny and so fresh. There are differences in there too, you know?"

As the world went into a standstill during the COVID-19 pandemic, stars like Kaitlin Olson (who was used to a busy lifestyle) suddenly found themselves constantly at home with their family. Speaking to Fatherly in 2021, the actor revealed how her family experienced the lockdown, noting that she, her husband, and her kids were extremely privileged. "We have a yard. We have different places where we could be like, okay, we're all sick of each other here, kids go outside," she shared. "Remote school was really hard and challenging. My kids were in second and third grade when this started and they had no idea about technology at all."

In the same interview, the sitcom star also shared how she parented her sons, stressing that consent and good manners were something she liked to focus on. "I just have two great kids. We talk a lot about consent and respect and leaving a place better than you found it," Olson explained. "They're at the point now where they're like, 'We get it, mom.' I don't know that it's much more than making sure that you live your life in a way that you're proud of, because your kids are always watching. They're polite and respectful."

Once life went back to normal post-pandemic, Olson's style became even more fun and unexpected. In a way, it seemed as if the actor missed dressing up for outings, which is why her outfits were a lot quirkier and unique on the other side. In 2022, she attended the American Cinematheque Award Ceremony, and for the occasion, she was dressed in a fun black-and-white Marchesa dress. What made the look even more memorable was the actor's half-updo — a hairstyle we rarely see her rocking.

In 2024, Kaitlin Olson talked to W Magazine, opening up about how it feels to be a woman in the still male-dominated world. "As women, we are groomed by society to be pleasant, smiling, kind, and likable to get what we need. That's not something that men have to deal with," she said. By speaking up about the inequality and difference in expectations, Olson undeniably spoke for many women across the globe, voicing their opinions as well. The sitcom star was never one to fear a strong opinion, and by speaking up about female empowerment, she undeniably won over even more hearts.

Similarly, she also shared her stance on the importance of being who you truly are. "It feels really good to recognize that being very clear and firm about what you expect — there's nothing about that that's unlikeable," Olson said. "People respect and trust you more when you're just authentically that." The actor added that playing Sweet Dee on "It's Always Sunny in Philadelphia" empowered her in numerous ways: "It feels good to play a character who's like, 'F— off! If you don't like it, that's fine. I don't care. I don't need you. I'm dealing with what's important, which is, for me in this show, three kids who need me.' That's why I like strong female characters."

Fashion-wise, 2023 and 2024 were marked by flowy floral maxi dresses for casual events — the star began rocking them in the early 2020s, and her love for the silhouette continued. For red-carpet events, Olson occasionally swapped the classic dress for trousers, giving off boss-lady energy even more!

In 2025, Kaitlin Olson turned 50, and it's safe to say that this upcoming decade will give us her boldest fashion yet. Don't believe us? 2025 is definite proof of that. When she attended the 2025 Disney Upfront event in New York City, the actor rocked a fun royal-blue Simkhai minidress with a delicate cutout pattern all over. Not bold enough for you? How about strawberry-blond hair? The actor showed up to the Go Gala in Beverly Hills, California, with the vibrant hair color and curtain bangs, showcasing just how excited she was to switch things up.

Speaking to Harper's Bazaar in 2025, the "It's a Wonderful Binge" star revealed who her role models were. " ... I have the honor and privilege of working with Jean Smart in Hacks — I always looked up to her," she gushed. "I was a huge fan of Annette Bening, Julia Louis-Dreyfus and Cate Blanchett. A million women are tremendous actors for numerous reasons." And if you ask us, Olson is definitely also one of them.

Now, if you care for more iconic sitcom stars, be sure to also check out "The Big Bang Theory" star Mayim Bialik's complete transformation!