Is this jacket too formal to wear as a blazer?

As mentioned by others -the fabric is a bit shiny and cheap. I am mystified as to why they call this a dinner jacket. Dinner jackets all have some common style points and this has none of them other than the slightly shiny fabric. The shiny fabrics might be a bit much for office and business -although it's perfect for going out after work, clubbing or anywhere you need to be a bit dressed up.

If you are young and trying to dress for the position career you want rather than the job you currently have then take cues from those in the job you want. If they wear jackets with business casual then wear a jacket. If they don't wear jackets then don't wear a jacket. In some offices a jacket is what sets management and future management apart from cubicle dwellers. If you have the confidence to wear a shiny jacket then go for it but there are much better choices. Personally I would recommend something that's labeled with "sport coat" "blazer" or "dress jacket" For a casual office leave it unbuttoned and no tie. I like this one here for a casual office: https://m.macys.com/shop/product/alfani-mens-slim-...

similar to the other one in color and tailoring but the style points are more sporty and casual which makes it more suited to a modern business casual office.

One more important point because I really have no idea of what your office is like and what your company does: If your whole office is young and smart and on the way up -like a high tech start up and you office is in a converted 19th century factory or glassed in loft type space -and fashion is a way to show you are young modern and ahead of the curve then a shiny jacket with slim fit pants and all the other young modern styles that go with it will show that you also are young, smart and ahead of the curve. High tech start ups have a dress style all their own and fashions that are a little apart from the norm and flashy are part of the package.

Its a bit cheap/shiney

its made from cheap fabrics (polyester, spandex & rayon) and quite honestly? It looks it

If you are a very young professional, you may be able to carry it off,

but 25+ I wouldnt wear it

it isnt formal, its more of a fashion piece

dinner jacket =/= blazer

You can wear that during business hours - in the professional field, and you can add jeans for Friday Casual.

If you're not sure, don't, but if you've got confidence to wear it, wear it. Does it matter what people think or say? I'd wear it, but I'm not a guy.

BTW: People usually go straight from work to dinner.