Unirea Slobozia was founded in 1955 under the name Combil Slobozia, initially under the tutelage of the Ialomița
combine for the production and industrialisation of pork meat, spending fifteen seasons in the Regional and County Championships, during which it competed under several names, including Avântul, Voința and Energia. In the
1969–70 season, Energia achieved promotion to
Divizia C after winning the
Ialomița County Championship and the promotion play-off against ITA București, the
Bucharest Municipal champions (0–0 at home and 2–1 away). In the summer of 1982, the club was renamed Unirea Slobozia, and under the guidance of Ion Păciulete, took the 1st place in Seria IV of the
1982–83 season promoting for the first time in
Divizia B. The squad was composed of following players: Soare, Ionescu, Tache, Drăguț, Cristea, Borș, Gogan, Mateiu, N. Nicolae, Gh. Nicolae, Lazăr, Lupu, Păun, Liviu, Vintilă, Constantinescu and
Damaschin. In the
1986–87 season, managed by Nicolae Dumitru as head coach in the first part of the season and
Emanoil Hașoti in the second part, Unirea reinforced with new players such as Istrate,
Dinu, Cîrîc, Mihale,
Gache,
Prepeliță, Roșu, Bătrâneanu and
Mustacă, was ranked 7th in Series I. The stay in second division lasted only two seasons, as in the
1987–88 season
Ialomițenii finished 16th in its series being relegated to Divizia C. In
Divizia B, Unirea competed in Series I, finishing the
1989–90 season in 13th place, just one point above the relegation line, followed by 8th place in the
1990–91 season and 9th place in the
1991–92 season. However, the
1992–93 season ended in last place out of 18 teams, resulting in relegation after four seasons in the second division. The club was re-founded in 2004 as AFC Unirea 04 Slobozia and secured a place in the
2005–06 Divizia C season, finishing 7th in Series II, followed by 6th place in
2006–07, 8th in
2007–08, 4th in
2008–09 under Marian Catană, and 3rd in
2009–10, a campaign in which Ion Răuță was replaced by Constantin Prepeliță towards the end. Under Prepeliță, the Yellow and Blues reached the fifth round of the
Cupa României, where they were eliminated 3–4 on penalties by
Viitorul Constanța, and went on to finish as runners-up in
2010–11, one point behind
Callatis Mangalia, with Viorel Gheorghe finishing as the series’ top scorer with 23 goals, thus achieving the club’s best finish in the last nineteen years. In the
2011–12, Constantin Prepeliță was named general director of the club, while Ion Ionescu took over as head coach, with Unirea winning its series and securing promotion to
Liga II three rounds before the end of the season. The squad included Dobre, Oprea, Judeanu, Lazăr, Stan, Roșu, Bozean, V. Toma, Cristian, Sescioreanu, Soare, Macare, Cristea, Ivașcă, Drăguț,
C. Toma,
Ibrian, Tudor, Patrianca, V. Gheorghe, T. Gheorghe, Zevedei, Stanciu, Ștefan, and Anghel. In the
2012–13 season, Ion Ionescu was replaced by
Marin Dună as head coach. Among the club’s signings was
Adrian Mihalcea, at the end of his career and regarded as one of the most valuable products of Slobozia football in the last twenty-five years. Dună led Unirea to the fourth round of the
Cupa României, where it was eliminated 1–3 by
Săgeata Năvodari, and to a 7th-place mid-table finish in Series I of Liga II. In 2013, Adrian Mihalcea ended his playing career and took over as head coach of Unirea Slobozia, leading the team to a 2nd-place finish in the regular season of Series I of the
2013–14 campaign, followed by 3rd place in the series play-off, behind
CSMS Iași and
Rapid București. The squad included, among others, Dobre, Oprea, Baruch, Stan, Antoniev, Soare, Lazăr, Tudorache,
C. Toma, Florea, Roșu,
N. Popescu,
L. Mihai, Macare, Ivașcă,
Ibrian, Patrianca, Dedu, Jianu,
Nanu, and D. Gheorghe. Unirea Slobozia started the
following season relying on the homogeneity of the squad led by Mihalcea, but had a disappointing campaign, being eliminated in the fifth round of the
Cupa României by
Viitorul Axintele after a 3–3 draw following extra time and a 1–3 defeat on penalties, and sitting 7th in Series I at the winter break. However, in February 2015, the club withdrew from Liga II due to financial problems, six rounds before the end of the regular season, and lost all remaining matches 0–3 to place 11th overall, continuing its activity only at youth level. season Unirea returned to
Liga III and competed in Series II in the
2015–16 season under Ion Ionescu as head coach and a squad composed largely of local young players, achieving a respectable 4th-place finish, and continued under his guidance in
2016–17, finishing 5th at the end of the campaign. Unirea began the
2017–18 season with Enache Costea as the new head coach, reaching the Round of 16 of the
Cupa României after defeating
ASA Târgu Mureș 4–0, with Nelu Bucă scoring all four goals, before losing 0–2 to
Politehnica Iași, and went on to finish 3rd at the end of the season. Costea then led Unirea to a 4th-place finish in the
2018–19 season and to the fourth round of the
Cupa României, where they were defeated 2–3 by
Sportul Snagov. The
2019–20 season was interrupted on 9 March 2020 after 16 rounds due to the COVID-19 pandemic, with Unirea in 1st place, three points ahead of
Mostiștea Ulmu, against whom they played a promotion play-off. Unirea won both legs 2–0, returning to Liga II after five years of absence. The squad led by Enache Costea comprised
Gurău, Poiană, Stoianovici,
Ibrian,
Dinu, Dumbrăvean, Comșa, Lazăr, Lemnaru, Suciu, Unguru, Gherasim, Danciu, Ad. Moldovan, Răduca,
C. Toma, Mihalache, Al. Muscă, M. Năstase, and Cr. Ene. After a series of poor results in the
2020–21 Liga II campaign, Unirea found itself in the lower half of the table. Enache Costea was replaced in December after fifteen rounds by
Adrian Mihalcea, who returned to Slobozia for a second spell and led the team to a 16th-place finish in the regular season. Unirea then finished third from bottom in Group B of the play-out and avoided relegation after winning the relegation play-off against
Comuna Recea, 3–2 on aggregate. In the
2021–22 season, Mihalcea led the Yellow and Blues to the Round of 32 of the
Cupa României, where they were eliminated 0–1 by
Politehnica Timișoara, and finished 6th in the regular season, a position they maintained in the promotion play-off group. Mihalcea left the club in June 2022 after being appointed by
top-flight side
Chindia Târgoviște and was replaced by
Costel Enache, who guided the team to the group stage of the
Cupa României, finishing 5th and being eliminated. He resigned in March 2023 after the team finished 7th in the regular season of the
2022–23 campaign and failed to qualify for the top six promotion play-off, and was replaced by his assistant, Enache Costea, who led the team to a 3rd-place finish in Group A of the relegation play-out. In the
2023–24 season, Mihalcea returned once again to Unirea and guided the team to the play-off round of the
Cupa României, where they lost 2–5 after extra time to
Hermannstadt, and secured a place in the top six promotion play-off, finishing 2nd in the regular season and winning the league by eight points, thus earning promotion for the first time in the club’s history to
Liga I. The squad included, among others,
Rusu, Șt. Georgescu, Ciupercă, Aioanei,
Dinu, Andreș,
C. Toma, G. Lazăr, Șandru,
Ibrian,
Pospyelov, D. Lazăr,
Dorobanțu, Bujor, Ekollo,
Coadă,
Atanase, Pacionel,
Purece, Lemnaru, Milotin,
Cojocari,
Dimitrov, Gîrbăcea,
Vlăsceanu, and
Afalna. ==Honours==