The matches will form part of busy schedule for new manager Brendan Rodgers as the Scottish champions play four games in ten days.
Celtic begin their Champions League qualifiers at the second round stage in mid-July and the tour will form an important part of their preparation.
Rodgers’ first game in the dugout will be on Thursday 30 June when Celtic face NK Celje, who finished fifth in the Slovenian top flight, at the Arena Petrol (kick-off 19.45 local time).
On Sunday 3 July Brendan Rodgers will then take his team the short distance across the border to meet three-time Austrian champions Sturm Graz in the Stadium Graz Liebenau (17.30 local).
Three days later Celtic will travel to the Slovenian capital Ljubljana to take on champions Olimpija Ljubljana in the Stozice Stadium (19.45 local).
Celtic will conclude their tour against NK Maribor on Saturday 9 July, in the Ljudski vrt – the same ground where Celtic met The Purples in the Champions League play-off two years ago (19.00). That match finished 1-1 but Maribor won 1-0 at Celtic Park to eliminate the Scottish side.
Maribor have also claimed the scalps of Rangers and Hibs in the Europa League in recent years.