2017–18 Third Amateur Football League (Bulgaria)

The 2017–18 Third Amateur Football League season is the 68th season of the Bulgarian Third Amateur Football League. The group is equivalent to the third level of the Bulgarian football pyramid with four divisions existing in it. The divisions themselves are geographically separated into North-West, North-East, South-East, and South-West, covering the football clubs of their respective zones. This is the second season after the reorganization of the Bulgarian football system, which saw the emergence of new competition formats, such as First and Second Professional Football Leagues.

To Third League
Promoted from Regional Divisions
 * Benkovski Byala
 * Spartak 1918
 * Botev Lukovit
 * Yantra 1919 Gabrovo
 * Yantra Polski Trambesh
 * Sokol Markovo
 * Tundzha Yagoda
 * CSKA 1948
 * Elin Pelin

Relegated from Second League
 * CSKA Sofia II
 * Spartak Pleven
 * Bansko
 * Levski Karlovo

From Third League
Relegated to Regional Divisions
 * Spartak Varna
 * Inter Dobrich
 * Kom Berkovitsa
 * Juventus Malchika
 * Lyubimets
 * Elhovo
 * Velbazhd Kyustendil
 * Chepinets Velingrad

Promoted to Second League
 * Chernomorets Balchik
 * Maritsa Plovdiv
 * Litex
 * Strumska Slava Radomir

a. CSKA Sofia II officially declined to participate in the South-West Third League and was dissolved.

Club movements between Third League and Second League
The champions of three Third League divisions gained promotion to the 2017–18 Second League: Chernomorets Balchik from North-East, Litex from North-West and Strumska Slava Radomir from South-West. Maritsa Plovdiv joined the promoted teams as runners-up of the South-East group because champions Zagorets refused to participate for financial reasons. In return, four teams were relegated to the Third League: CSKA Sofia II, Spartak Pleven, Bansko and Levski Karlovo. CSKA Sofia II was dissolved; as a result, Svoboda Peshtera (16th in 2016–17 South-West Third League) was spared from relegation to regional divisions.

Club movements between Third League and the Regional Groups

 * North-East: Spartak Varna and Inter Dobrich were relegated last season to regional divisions. The new teams, coming from the regional divisions, are Benkovski Byala (champions of RFG Ruse) and Spartak 1918 (runners-up of A2 RFG Varna). On 21 June 2017, Spartak Varna merged with Spartak 1918.
 * North-West: Kom Berkovitsa and Juventus Malchika were relegated from last season to regional divisions. The new teams, coming from the regional divisions, are Botev Lukovit (9th in RFG Lovech), Yantra 1919 Gabrovo (runners-up of RFG Gabrovo) and Yantra Polski Trambesh (champions of A RFG Veliko Tarnovo).
 * South-East: Lyubimets and Elhovo were relegated from last season to regional divisions. The new teams, coming from the regional divisions, are Sokol Markovo (runners-up of A RFG Plovdiv) and Tundzha Yagoda (runners-up of RFG Stara Zagora).
 * South-West: Velbazhd Kyustendil and Chepinets Velingrad were relegated from last season to regional divisions. The new teams, coming from the regional divisions, are CSKA 1948 (champions of RFG Sofia (capital)) and Elin Pelin (champions of RFG Sofia (province)). Initially, Kyustendil (champions of RFG Kyustendil) was supposed to participate as winners of the promotion play-off. However, on 14 July 2017, Kyustendil withdrew from participation so the Bulgarian Football Union scheduled an additional play-off between the losers of the promotion play-offs. On 31 July, Bratsigovo refused participation so Elin Pelin was approved as new member of the South-West league.