The 18-year-old, who is preparing to sit her A-levels in English and media at Jersey College for Girls, was crowned the winner during a ceremony at St Clement’s Parish Hall.
Courtney Anders and Charlotte Volante were the runners-up.
Miss Forrest, who hopes to study English at university and is considering a career as a primary school teacher, said: ‘I was delighted to win the title, especially seeing as it was my first time entering the competition.
‘I feel very proud to represent the parish because I feel the parish of St Clement contributes so much to the Island and I really wanted to give something back.’
The title of Miss Junior St Clement went to Lacey Le Boutillier (11), who is a pupil at St Clement’s School.
Miss Le Boutillier is in her final year of primary school and is due to start at Beaulieu Convent School in September.
Her mother Lucy Le Boutillier described her daughter as very studious, adding that she enjoys maths. Outside of school Miss Le Boutillier plays netball and takes part in street dance.
The judges on the evening were Emma Matthews, who previously won both Miss St Clement and Miss Battle, Deputy Lindsay Ash and Tony Perkins, who was the previous Chairman of the St Clement Battle of Flowers Association and Jersey Battle of Flowers Association.
