No, Howard Stark did not know it was Tony. This is evident from the fact that he was surprised when Tony revealed himself at the end of the movie. However, there are some fan theories that suggest Howard may have had an idea that it was Tony. One theory is that Howard knew about Tony's abilities and knew that he would be able to build the suit. Another theory is that Howard saw something in Tony's eyes when they met, which led him to believe it was him. However, these are just theories and there is no concrete evidence to support them.