Provincial legislature: 1994–2019

Kiviet became a member of the legislature in the 1994 general election.^{[citation needed]} She also served as provincial treasurer of the ANC's Eastern Cape branch from 1996 to 2003,^[1] serving under ANC provincial chairperson Makhenkesi Stofile. Pursuant to the 2004 general election, she was elected as Speaker of the Eastern Cape Provincial Legislature. She held that position until the conclusion of the legislative term in the 2009 general election, after which she was elected to succeed Mbulelo Sogoni as Premier of the Eastern Cape.^[3]

Kiviet took office as premier on 6 May 2009,^[1] becoming the fifth person and the second woman to hold the job.^[2] According to the Mail & Guardian, her election was unexpected, with Mbulelo Sogoni and Mcebisi Jonas having been viewed as the frontrunners for the position.^[2] In June 2012, she was rated as the worst-performing provincial premier by the South African Public Service Commission.^[4]

In the next general election in 2014, Kiviet was re-elected to the Eastern Cape Provincial Legislature, ranked 23rd on the ANC's party list,^[5] but she was succeeded as premier by Phumulo Masualle and instead was elected to a second term as Speaker.^[6] While she was in that position, in December 2017, the ANC's 54th National Conference elected Kiviet to a five-year term as a member of the party's National Executive Committee; by number of votes received, she was ranked 54th of the 80 ordinary members elected.^[7]

National legislature: 2019–present

In the 2019 general election, Kiviet did not seek re-election to the provincial legislature but was instead elected as a Member of the National Assembly, the lower house of South Africa's national Parliament; she was ranked 42nd on the ANC's national party list.^[5] After the election, President Cyril Ramaphosa appointed her Deputy Minister of Public Works and Infrastructure. She took office on 30 May 2019 and deputised Minister Patricia de Lille.^[8] In December 2022, at the ANC's 55th National Conference, she was re-elected to the National Executive Committee, ranked 43rd by number of votes received.^[9]

On 6 March 2023, Ramaphosa announced a cabinet reshuffle in which Kiviet was promoted to Minister of Public Service and Administration.^[10] That post which had been filled by Thulas Nxesi in an acting capacity since Ayanda Dlodlo's resignation in 2022.