The 29-year-old classically trained musician, whose real name is Susanna Marie Cork, is representing Britain with an anthemic song called Storm.
She is one of 26 acts taking part in the final, which is taking place in Lisbon and also includes a heavy metal band, opera singers, a singing violinist and some miniature dancing robots.
It is 21 years since the UK last won the Eurovision Song Contest and nine years since the country finished inside the top 10.
But SuRie believes her mix of music and “high-end technology” will make her stand out in a crowded field of competitors.
“It’s a really special collaboration between the UK team and the Portuguese team over here,” she told the Press Association.
“It’s got a really beautiful concept... a kind of light tunnel that I can move in and out of, supporting the story and enhancing the beats of the song.
“It creates a really strong atmosphere on stage, letting the music - the melody and the lyrics - do their thing.”
Tonight’s final is the climax of the week-long Eurovision contest, which has already seen its share of controversy and surprises.
Russia made a shock exit from the competition during Thursday’s semi-final - the first time the country has failed to qualify for the final since the current system was introduced.
And the contest’s organisers have barred China from showing the final, after one of its TV stations censored LGBT elements of Tuesday’s semi-final.
One of these was Ireland’s song Together, performed by Ryan O’Shaughnessy, which included two male dancers depicting the end of a relationship.
Ireland - which holds the record for most Eurovision wins (seven) - is back in the final for the first time since 2013.
O’Shaughnessy will perform third from last, while SuRie will be ninth to appear.
“I think that’s a wonderful position to be in,” she told PA. “I’m not going to be sat backstage twiddling my thumbs and getting really nervous, just waiting and waiting and waiting.
“I’ll present my song and then I can enjoy the rest of the night.”
The UK did not have to compete in the semi-finals as it gets an automatic place in the Eurovision final, thanks to its status as one of the biggest financial contributors to the European Broadcasting Union.
This year’s final is also notable for:
- A return appearance by Norway’s Alexander Rybak, who won Eurovision in 2009
- Half the acts coming from countries in western Europe, the greatest proportion since 2014
- No appearance by Azerbaijan, who failed to qualify for the first time since their debut in 2008
- Australia’s fourth appearance in the contest, represented by Jessica Mauboy who previously appeared as an interval act during one of 2014’s semi-finals
TV host Graham Norton will be the commentator for BBC One’s coverage of the final, which begins at 8pm on Saturday evening.
Ken Bruce will present BBC Radio 2’s coverage, while former Bake Off host Mel Giedroyc will deliver the result of the UK vote live from London.