Hearts will face Fiorentina, Istanbul Basaksehir and Latvian champions RFS in Europa Conference League Group A.
Fiorentina were seventh in Italy’s Serie A last season while Basaksehir finished fourth in Turkey’s Super Lig and RFS won their first domestic title.
The group fixtures will take place on 8 and 15 September, 6, 13 and 27 October and 3 November.
Robbie Neilson’s side were knocked out of the Europa League at the play-off stage by Zurich.
Hearts, who were the first team drawn from the third pot of seeds, finished third in last season’s Scottish Premiership and reached the Scottish Cup final.
The Tynecastle club are returning to European group-stage football for the first time in 18 years.
Vincenzo Italiano’s Fiorentina have won one and drawn one of their opening domestic fixtures and overcame play-off opponents Twente to reach the Conference League group stage, beating the Dutch side 2-1 on aggregate.
Basaksehir, managed by former Turkey, Inter Milan and Newcastle midfielder Emre Belozoglu, are unbeaten after three league games, winning two, and beat Israel’s Maccabi Netanya, Iceland’s Breidablik and Belgians Royal Antwerp to in Conference qualifying.
Riga-based RFS, who are third in their domestic league after 25 games, defeated Maltese side Hibernians before edging Northern Ireland champions Linfield on penalties in the play-off round.
Hearts have two wins, a draw and a defeat so far in this season’s Scottish Premiership and host St Johnstone on Sunday.
