Show Title on Single Page - theme option

I have the show title on single page turned on. I find that if I turn it off the webpage looks better. (I use single post pages)
If I turn it off will that mess up my SEO. A title is pretty important on-page SEO.
or
If it is the single page is it better because it is closer to the content?

Now I am really confused.

Anyway, thank you for taking time to consider my question.

Titles does often use <h1>,<h2> or <h3> tags. If that's the case it might effect your SEO.
Mabye you can just change the size of the title (to smaller)? It's pretty common to have a headline what the content is about, not sure if I would've removed the title myself..