If you have an undergraduate degree in metallurgy you can find employment as a metallurgist, similarly with chemistry. However trying to find employment as a physicist without a PhD is next to impossible. So my question is if you only have a Bachelor of Science in physics could you be considered a physicist or do you need a PhD first?

Jobs that require some level of degree specify what it is. No one really cares if yo call yourself a physicist or not, nor would they put it in job description (unless they do not know what they want, which is a bit of a warning sign). So you would typically read something like: "requires a BSc/MSc/PhD in XXX or related field".

So my question is if you only have a Bachelor of Science in physics could you be considered a physicist or do you need a PhD first?

You will find jobs in industry, banking & finance and engineering that require only a Bachelor's degree or similar. This should be clear on the job advert; they usually state the minimum educational requirements and you can also get some idea from the experience they are asking for.

 

To be considered a 'physicist' depends on who is considering you. I have seen jobs looking for 'physicist' meaning only a BSc. Typically though I would say that 'physicist' means with a PhD in physics or closely related subject. To me, it means that and a publication or two.

 

In short, it is all relative.