Are you using “jeans” to mean “denim” or “pants”. Are you talking about work or dress?
In general, “denim”, the fabric form which “bluejeans” or “dungarees” are made is used for physical work, and is considered to be undressy. It is what you would wear to work if you are on a construction site, not what you would wear to work in an formal office (especially in the well dressed East Coast of the US, other areas are less formal). It would be inappropriate to wear when visiting the President or the monarch, or appearing in court – so, kal vehomer, in shul.
If you are talking about “jeans” to mean “pants” the answer is the same as to whether you wear “pants” – which depends on a variety of personal factors.