Opera icon logo is the current "O" letter logo of the web browser Opera. The logo was officially released with Opera 33 on October 27, 2015, replacing the Opera icon logo v.2013.[source]
According to Opera, the company "envisions its new logo as a portal quickly connecting users with what they’re looking for on the web. The 3-dimensional "O" symbolizes a gateway that leads users to more: more content, more discoveries, more answers, more communication, more fun, more data savings, more of life".[source]