Body language experts say the trick is to distract your mind and focus on things that don't make you nervous.
Here are five tricks for doing just that:
1. Recall a memory that inspires positive emotions.
One simple way to quell feelings of nervousness is to momentarily transport yourself to a time in which you felt self-assured and at ease. You can do this just before entering the room, or during the interview itself.
"Think of a time on the job, or in your personal life, when you experienced a success ... Notice how you feel, tell yourself that story, feel those emotions and merge those positive emotions with the new story of your job interview success," says Patti Wood, body language expert, coach, and author of "Snap: Making the Most of First Impressions, Body Language, and Charisma."
"We create and experience stories in the emotional right hemisphere of our brain," she explains. "When we recall and retell these stories, we re-experience the feelings that accompany them. By using this merging technique, you can bring positive emotions and success into any situation."
2. Create a secret gesture that corresponds to positive experience.
To take trick No. 1 one step further, Wood suggests creating your own personal gesture that's associated with a positive experience you've had in your life. (This works well if you don't have a specific memory in mind to think back to.)
Wood says she once worked with a client who couldn't think of a positive scenario that would help him relax during a job interview, so she told him to recall the emotions he felt during an activity or situation he enjoyed - in this case, sailing.
Mustering up these positive emotions, they worked to create a body movement - placing his hand on the side of his leg - that would jog his memory of the contentment and confidence he felt while sailing.
The next time he felt nervous during a job interview, briefly placing his hand on his leg activated those positive feelings, she says.
3. Silently repeat a mantra.
Another way to calm yourself is to silently repeat a personal mantra, says Dr. Lillian Glass, behavior analyst, body language expert, and author of "The Body Language of Liars." A pacifying message will works well when you're wrapped up in your own anxiety. "You can tell yourself to relax, that everything will be just fine," she explains.
Cater to your own suspense-driven emotions and conceptualize a message that works best, whether it's more soothing or upbeat. When you're feeling overwhelmed, silent reassurance - whether it's that you will accomplish your goals, or just that you'll get through this stressful situation - will bring your mind back to a more tranquil state.
4. Be interested, not interesting.
One major flaw people make while trying to ensure a good first impression - during a job interview or otherwise - is trying too hard to appear interesting, while disregarding what the other person has to say.
"Be interested in what the other person is saying," says Glass. "Focus on being interested, not interesting."
Once you stop obsessing over what intelligent or witty thing to say next, and actually concentrate on the conversation at hand (not just your end), you'll have an easier time navigating the discussion, and less of a chance of getting lost in your own thoughts - which can make anyone extremely nervous.