What term means someone with no tact?

Is there a term to describe someone with no tact, someone who frequently says things that offend others? Malicious intent it not necessary, but a lack of awareness.

Sample sentence: Sally is a ___ and is always saying things that offends her coworkers.

Solution 1:

Someone who lacks tact is tactless.

Looing at the synonyms of tactless, we have boorish

Rough and bad-mannered; coarse.

Someone who is boorish is a boor

A rough and bad-mannered person.

Which can be put in the sample sentence as

Sally is a boor and is always saying things that offends her coworkers

Solution 2:

To look for an actual noun is difficult. But when somebody lacks tact, they often say or do things that are impolite or unconsidered and that make other people uncomfortable. It's how such a person makes other people feel that I think is key.

As such, I think a close noun would be embarrassment:

[Merriam-Webster]
1 a : something that embarrasses
// the scandal was a major embarrassment

So:

Sally is an embarrassment and is always saying things that offend her coworkers.

It's often applied more to things than to people, but I have heard it applied to people too. If applying it to a person, I think it comes quite close to the noun version of tactless.

Having said that, I think using the adjective tactless would still be a better general choice when it comes to describing such a person—mainly because there is no noun that carries exactly the same meaning.