About Us.

Mackenzie Collier Interiors is a full-service residential & commercial interior design team in the heart of downtown Phoenix, specializing in sustainable, functional design. 

Since 2011, our interior design team has serviced clients throughout Phoenix metro and beyond, completing projects in the Northwest, Midwest, and East Coast. MCI team members hail from around the country, and we apply our diverse experiences and perspectives to each client project. 
At Mackenzie Collier Interiors, we focus on working closely with clients to create personalized, stress-free design experiences, helping families and businesses express themselves through their unique spaces. We are committed to creating beautiful designs that not only look great but also support your lifestyle—taking our own tastes out of the equation and focusing on defining and developing your personal style. 

Screen Shot 2019-04-10 at 3.47.04 PM.png


Screen Shot 2019-05-21 at 11.24.34 AM.png

Mackenzie Collier

Owner, Principal Designer
B.S. Psychology, Michigan State University
A.A.S. Interior Design, Harrington College of Design

Throughout her career, Mackenzie has gained a reputation for her unique approach to creating spaces that reflect her clients’ distinctive styles & interests. With a diverse portfolio of both residential and large-scale commercial projects, she has honed her skills in space planning and project management, placing emphasis on universal design practices and sustainability. 

Prior to graduating with honors from Harrington College of Interior Design in downtown Chicago, Mackenzie earned her BS in Psychology from Michigan State University, where she focused on child and family psychology. The marriage of these educational backgrounds gives her the uniquely adept ability to communicate with clients and interpret their specific needs, and to understand the distinct ways individuals use their various spaces.

Mackenzie has built her business with her core values of community building, positivity and integrity in mind. She teaches and speaks nationally about business practices and interior design and is part of an ever-growing community of business owners who are expanding beyond the traditional business model.

Mackenzie constantly searches for new inspiration through travel, art, music, and nature. She loves highly functional spaces that have clean lines and natural light pouring in. She is a firm believer that the best design solutions are also the simplest and that kindness always comes back to you. 

Screen Shot 2019-04-10 at 4.00.27 PM.png

Aleah Carr

Senior Interior Designer, Project Manager
B.S.D. Interior Design, Arizona State University

Specializing in AutoCAD and SketchUp, Aleah brings a unique, tech-savvy form of concept development to the team, along with a creativity and originality that is all her own. Born and raised in El Paso, Texas, Aleah relocated to Phoenix to attend Arizona State University, where she earned a bachelor's degree in Interior Design. She joined the MCI team as an intern and has been bringing fun, funky elements to the table ever since. Throughout the years, Aleah has worked her way to the top of the ranks as Interior Designer and Project Manager, serving as the primary contact for clients and contractors and overseeing project details from start to finish. Outside the office, if she’s not stuck with her nose in a book, you can find her curating her collection of indoor plants or hanging out downtown.

Screen Shot 2019-04-10 at 4.01.24 PM.png

Yoselin Castro

Senior Interior Designer
A.A. Interior Design, Phoenix College
B.S. Interior Design, Northern Arizona University

Yoselin received her Associate's Degree in Interior Design from Phoenix College and her Bachelors of Science in Interior Design at Northern Arizona University. She is determined and committed to bringing a creative and vibrant view in her designs as she skillfully balances form, function, and budgets. Yoselin is passionate about interior spaces and driven to enhance the way people live, work, and play in their everyday environments. She gains inspiration by exploring new places, as well as through her love for nature, art, and fashion. When she is not in the design studio, Yoselin likes spending time with her family, baking vegan recipes, and practicing yoga.

Screen Shot 2019-04-10 at 4.04.53 PM.png

Karleigh Handwork

Interior Designer
B.S. Interior Design, Art Institute of California, San Diego

After falling in love with interior design at a young age, Karleigh received her Bachelors degree from the Art Institute of California, San Diego. During her studies, she discovered her favorite part of interior design is the potential of color to transform a space. Karleigh loves how powerful and personal this element of design can be, and likes using color to highlight clients' personalities in their spaces. Moving to Phoenix, Karleigh was eager for new experiences and to see how beautiful the desert can be.  MCI's team environment of dedicated interior designers who collaborate and explore together, was exactly what she was looking for.  In her free time, she enjoys taking walks in nature, socializing with friends and finding creative ways to add to the decor in her home.

Screen Shot 2019-04-18 at 1.50.30 PM.png

Maddy DeVries

Interior Designer
B.S. Interior Design, University of Bridgeport

During Maddy's years at the University of Bridgeport, she was ASID UB chapter president for two years and then moved onto becoming a student representative to the Connecticut ASID board; she graduated magna cum laude and aims to continue growing in the Interior Design community in Phoenix. While spending summers in Oregon, she interned for Harry & David in their photo studio assisting the photographer, food stylist, and art director. The process of styling for the shoots inspired her to blend the world of photography and design, seeing its applications in various settings. These experiences now allow her to use light, texture, and color to create a meaningful 3D perspective in all her designs. Maddy recently located to Phoenix and when she isn't in the studio, you can find her with her husband and puppy finding new places to enjoy the desert atmosphere. 

Screen Shot 2019-04-10 at 4.01.39 PM.png

Monica Milewski

Studio Manager
B.S. Psychology, Loyola University Chicago
M.S. Child Development, Erikson Institute
M.S.W. Social Work, Loyola University Chicago

Always seeking to grow both personally and professionally, Monica aims to add her zest for organization and client connection to the MCI team! Originally fueled by a desire to understand people on a deeper level, she received her Masters of Social Work and Child Development back in her hometown of Chicago. Life shifted her direction into the world of design, and she spent three years as a Project Coordinator at a kitchen and bath showroom. Deciding it was time for a change from the cold, cloudy midwest, Monica sought more sunshine and moved to Phoenix. Here, she seeks to engage with the community and share how MCI can transform their spaces into interiors that are a beautiful showcase of personality. Monica hopes the desert landscape will serve as inspiration for her creative hobbies of photography, painting, and gardening.  

Screen Shot 2019-05-21 at 3.45.27 PM.png

And Ranger, the wonder dog.

Security Intern

Ranger is the new kid on the team and he has very big dog booties to fill! He's in training for the Regional Head of Security position that was previously occupied by the very best good boy, Vern. Ranger hails from Mexico City and has done a lot of traveling in his rather short life so far. He is a guy who takes naps seriously and provides the team with lots of laughs while he's mastering his athletic abilities. He encourages the team to get up and move around throughout the day because he needs potty breaks every 20 minutes or so. He'll be making lots of appearances on our Instagram account, so be sure to follow us @MackenzieCollierInteriors!