The 2018–19 Croatian First Football League (officially Hrvatski Telekom Prva liga for sponsorship reasons) was the 28th season of the Croatian First Football League, the national championship for men's association football teams in Croatia, since its establishment in 1992.
On 23 April 2018, Croatian Football Federation announced that the first stage of licensing procedure for 2018–19 season was complete.
For the 2018–19 Prva HNL, only eight clubs were issued a top level license: Dinamo Zagreb, Gorica, Hajduk Split, Inter Zaprešić, Lokomotiva, Osijek, Rijeka and Slaven Belupo.
All of these clubs except Gorica were also issued a license for participating in UEFA competitions.
At the end of the season, ninth-placed team Istra 1961 contested a two-legged relegation play-off tie against Šibenik, runners-up of the 2018–19 Croatian Second Football League.