India's Nehal Chudasama failed to make it to the Top 20.
Ms Gray was ecstatic as she took her first walk as Miss Universe in a red gown. She was crowned by Miss Universe 2017 Demi Leigh Nel-Peters, who comes from South Africa.
In the final question round, Ms Gray was asked about the most important lesson she has learnt in life and how would she apply it in her time as Miss Universe.
She said: "I work a lot in the slums of Manila and life there is very poor and sad. I have always taught myself to look for the beauty in it, to look for the beauty in the faces of the children, and I would bring this aspect as a Miss Universe to see situations with a silver lining and to asses where I could give something and provide something.
"And if I could also teach people to be grateful, we could have an amazing world where negativity would not brew and foster, and children would have a smile on their face."negativity."
The winner, who pipped 93 other contestants to win the title, has a love for the arts and holds a Master Certificate in Music Theory. She is an adventure junkie and is passionate about her love for Filipino dishes including adobo, balut and the sweetest mangoes in the world.
As for her philanthropic side, she is an HIV/AIDS advocate at Love Yourself PH and volunteers as a Teacher's Assistant to the students of Young Focus NGO, according to the official Miss Universe website.
South Africa's Tamaryn Green was named the first runner-up. A medical student, her favourite quote is from Mahatma Gandhi: "Be the change you want to see in the world."
The second runner-up, Miss Venezeula Sthefany Guterrez is studying to be a lawyer in her home country.