Erro ao subir meu Projeto Web - Tomcat

Olá, estou usando Tomcat 8 e quando eu rodo o meu Projeto ele está apresentando um erro.

java.lang.ClassNotFoundException: javax.faces.webapp.FacesServlet
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1308)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1142)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:518)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:499)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1102)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1038)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4997)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5289)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)