self-opinionated

[ self-uh-pin-yuh-ney-tid, self- ]

/ ˌsɛlf əˈpɪn yəˌneɪ tɪd, ˈsɛlf- /

conceited; having an inordinately high regard for oneself, one's own opinions, views, etc.

stubborn or obstinate in holding to one's own opinions, views, etc.

Also self-o·pin·ioned

[self-uh-pin-yuh nd] /ˌsɛlf əˈpɪn yənd/.

Origin of self-opinionated

First recorded in 1665–75

Knew him well, the selfish old pig; as conceited, self-opinionated an old fool as ever lived in all England.

Babylon, Volume 2 (of 3) |Grant Allen
For the rest, he was a peevish, self-opinionated old man, and a rank impostor.

Jimmy Quixote |Tom Gallon
The Deacon is very self-willed, stubborn and self-opinionated, and will listen to no reason when it clashes against his set views.

The Deacon |Horace C. Dale
She had become therefore somewhat querulous, and self-opinionated in her discussions with her friend.

La Mere Bauche |Anthony Trollope

But that was only because she was not self-opinionated, and was anxious, more anxious than any woman in all the North.

Northern Lights |Gilbert Parker

self-opinionated

having an unduly high regard for oneself or one's own opinions

clinging stubbornly to one's own opinions