Build a following on the comedy club circuit. A comic actor usually begins his career as a stand-up comedian, typically using the popularity of his stand-up routine as a springboard into the world of acting. This means writing your own material and performing at local and regional comedy clubs, even if you begin by performing on amateur nights. If your perform on the amateur circuit long enough and prove to be a popular draw, you can begin performing comedy events for pay.
Get an agent. You won't need one while you're performing at amateur events, but once you start performing professionally, you can get a booking agent to help find you more high-profile shows. The odds of getting a job in a movie while you're playing amateur nights in small clubs are almost non-existent. An agent can help open doors for you that you may not be able to open on your own. There are numerous agencies that represent comedians, which can be accessed online (See Resources). Contact these agencies with your bio, a picture and a short video of your performance. Many of these agencies can get you bookings for events, including auditions for roles in movies.
Prepare yourself to go where the movie business is. While it isn't essential to relocate, if you're serious about a career as a comic actor, you'll want to at least consider the possibility of moving to the East or West Coast, or a city such as Atlanta or Chicago, where the film industry is more prevalent. This will make it easier for you to find and attend auditions for movie roles.
Get an acting coach. While performing stand-up is a good way to sharpen your comedic skills, you'll still need to hone your acting skills. Being funny isn't always enough to get you into the movies. You'll need to act as well. You can find a list acting coaches online; one or more may be right for you. Be honest and critical of yourself. If you believe you have acting abilities, you may not need an acting coach, but if you feel your skills as an actor are limited, be open to acting lessons.
Develop your personality. This is important for a comic actor. The process is ongoing and should be your focus as you pursue a career as a comic actor. Robin Williams, Adam Sandler, Tim Allen, Jeff Foxworthy and Jim Carrey all bring an immediate and recognizable personality to the screen. Developing your own personality is probably the single most important way you can be successful as a comic actor.