The 2018–19 3. Liga was the 26th season of the third-tier football league of Slovakia since its establishment in 1993. The league is composed of 63 teams divided in four groups of 16 teams each; only 3. liga Východ (East) includes 15 teams. Teams are divided into four divisions: 3. liga Bratislava, 3. liga Západ (West), 3. liga Stred (Central), 3. liga Východ (Eastern), according to geographical separation.