In 2013, Hoey was elected as the Deputy President and Campaigns Officer for UCC Students' Union. At the Union of Students in Ireland congress in April 2014, Hoey was elected as the Vice President for Equality and Citizenship. In March 2015, Hoey was re-elected to the same position. During 2014 and 2015, in the lead up to the referendum of the Thirty-fourth Amendment of the Constitution of Ireland, known as the Marriage Equality referendum, Hoey used her role as USI Equality and Citizenship Officer to mobilise students across the country. She organised USI’s flagship Pink Training event in Cork in November 2014. The weekend conference focused heavily on training students in campaigning for a Yes vote and it was attended by a record number of students. In the months leading up to the vote in 2015, Hoey traveled across the country conducting training events for students on messaging and canvassing. Hoey's mobilisation work accumulated with an idea of a ‘voter motor,’ a campaign that was launched by USI in the final week of the campaign to encourage people to give their fellow citizens a lift to the polling stations. During Hoey's second term as the UCI Vice President for Equality and Citizenship, she was appointed Deputy President of USI to USI President Kevin Donoghue. Hoey then served as President of the Union of Students in Ireland from 2016 to 2017. During her tenure as USI President, an estimated 15,000 students took part in the #EducationIs demonstration in Dublin, to show student opposition to income contingent loan schemes. In March 2017, Hoey presented to the Citizens' Assembly at the fourth meeting of the Citizens' Assembly on the Eighth Amendment of the Constitution. Hoey was also a board member of the Higher Education Authority.
Political work
Hoey took up the role as the Education and Training officer for the Coalition to Repeal the Eighth Amendment in 2017. Soon after, Hoey was appointed as the National Canvassing Coordinator and a spokesperson for Together For Yes working for long-time campaigner Ailbhe Smyth. During the 2018 Irish presidential election, Hoey was appointed Volunteer Director for Campaign to Re-elect Michael D. Higgins. Shortly after, Hoey was employed as the Women and Youth Development Manager with the Labour Party from 2019 to 2020.
In February 2020, Hoey unsuccessfully contested the 2020 Irish general election as the Labour Party candidate for the Meath East constituency, receiving 874 first preference votes. In March 2020, Hoey successfully contested the 2020 Irish Seanad election as the Labour Party candidate for the Agricultural Panel. Hoey was elected on the 20th count receiving 94,186 votes.
Seanad Éireann
Hoey was one of five Labour Senators to seek a High Court ruling to determine whether the Seanad can sit without all 60 members. On July 7th, 2020, Hoey was appointed Party Spokesperson on Higher Education, Innovation and Research.