The 2017–18 Liga IV was the 76th season of the Liga IV, the fourth tier of the Romanian football league system. The champions of each county association play against one from a neighboring county in a playoff to gain promotion. From this season the counties were divided into 7 regions, each consisting of 6 counties and the draw was made on 28 February 2018, with 3 months and a half before the first matches.
Promotion play-off
The matches are scheduled to be played on 16, 23 and 30 June 2018.
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|colspan="3" style="background-color:#97DEFF"|Region 1 (North-East) |colspan="2" style="background-color:#97DEFF"| ||0–1||0–1 ||w/o||w/o ||5–0||1–0 |- |colspan="3" style="background-color:#97DEFF"|Region 2 (North-West) |colspan="2" style="background-color:#97DEFF"| ||0–0||2–0 ||6–0||4–2 ||w/o||w/o |- |colspan="3" style="background-color:#97DEFF"|Region 3 (Center) |colspan="2" style="background-color:#97DEFF"| ||1–0||2–0 ||w/o||w/o ||2–0||1–3 |- |colspan="3" style="background-color:#97DEFF"|Region 4 (West) |colspan="2" style="background-color:#97DEFF"| ||0–1||2–1 ||4–0||3–0 (forfait) ||5–0||6–0 |- |colspan="3" style="background-color:#97DEFF"|Region 5 (South-West) |colspan="2" style="background-color:#97DEFF"| ||8–0||1–0 ||2–1||1–0 ||w/o||w/o |- |colspan="3" style="background-color:#97DEFF"|Region 6 (South) |colspan="2" style="background-color:#97DEFF"| ||1–1||2–4 ||0–7||1–10 ||5–1||1–1 |- |colspan="3" style="background-color:#97DEFF"|Region 7 (South-East) |colspan="2" style="background-color:#97DEFF"| ||2–2||0–3 ||0–3||1–5 ||0–4||4–3 |}
County leagues
Alba County
Arad County
Argeș County
Bacău County
Bihor County
Bistrița-Năsăud County
Botoșani County
Brașov County
Brăila County
Championship play-off
The teams started the championship play-off with half of the points accumulated in the regular season.
Championship play-out
The teams started the championship play-out with half of the points accumulated in the regular season.
Bucharest
Regular season
Championship play-off
The championship play-off played in a single round-robin tournament between the best four teams of the regular season. The teams started the play-off with the following points: 1st place – 3 points, 2nd place – 2 points, 3rd place – 1 point, 4th place – 0 points.
Buzău County
Relegation play-off
The 14th and 15th-placed teams of Liga IV Buzău faces the 2nd-placed teams in the two series of Liga V Buzău.
Caraș-Severin County
Călărași County
Cluj County
Constanța County
Covasna County
Dâmbovița County
Dolj County
Championship play-off
At the end of the regular season, the first four teams will play a Championship play-off and the winners crowned as county champions and qualify to the promotion play-off to Liga III. The teams will start the play-off with the number of points gained in the regular season only against the other qualified teams.
League Cup
The teams which was ranked 5th to 12th places in the regular season played in the League Cup to establish the final standings. In the League Cup, each tie was played on a home-and-away two-legged basis. If tied on aggregate, the away goals rule was used.
First round
First Leg: 5 and 6 May. Second Leg: 11 and 12 May.
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||2–5||0–9
||7–2||2–1
||0–4||0–3
||1–4||0–1
|}
Second round
First Leg: 19 May. Second Leg: 26 May.
5-8 places
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||1–1||1–6
||4–3||0–1
|}
9-12 places
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||4–4||1–5
||5–3||2–3
|}
Third round
First Leg: 2 June. Second Leg: 8 and 10 June.
5-6 places
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||1–2||1–3
|}
7-8 places
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||8–1||8–5
|}
9-10 places
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||5–3||3–4
|}
11-12 places
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||6–1||0–3
|}
Galați County
Giurgiu County
South Series
North Series
Championship play-off
The championship play-off played between the best two ranked teams in each series of the regular season. All matches were played at Comunal Stadium in Bolintin-Deal on 5 and 7 June 2018, the semifinals and 10 June 2018, the final.
Semi-finals
Final
Singureni won the 2017–18 Liga IV Giurgiu County and qualify to promotion play-off in Liga III.