8-9 August WRE Finnish TrailO Championships, SW of Tampere, Finland. PreO + TempO. Details (in Finnish) here
14-16 August   Bukowa Cup, Szczecin, Poland.  TempO + PreO (not now WRE)
19-20 September WRE, ECTO Nordic Match, Løten, Norway. TempO (not in ECTO) + 2 x PreO
25-27 September WRE Falco Cup, Rykantai, Lithuania. TempO + 2 x PreO + Sprint PreO. Details here
3-4 October WRE, ECTO Rak TrailO, Rakov Skocjan, Cerknica, Slovenia. 2 x Preo. Details here
10-11 October WRE, ECTO Siben TrailO Cup, Asiago, Italy, TempO + PreO + Sprint PreO. Details here
17-18 October WRE FIN TrailO, Turku, Finland. TempO + PreO + Sprint PreO. Details here
7-8 November WRE, ECTO Slovakia TrailO Weekend, TempO + PreO + Sprint PreO. Details here
14-15 November WRE, ECTO Hungarian TrailO, Vas, Hungary. TempO + PreO
12-16 May   European TrailO Championships 2020, Espoo, Finland
20-24 July   World TrailO Championships, Poland
1-7 July   World TrailO Championships, Zakupy, Czech Republic
3-7 August   European TrailO Championships, Turku, Finland

WRE = IOF World Ranking Event

ECTO = European Cup in TrailO

The following events usually have one or more TrailO competitions along with FootO competitions:

Portugal O-meet, February (PreO)

Lipica Open, Slovenia (PreO)

JK, Easter weekend (TempO + PreO)

British Orienteering Championships and British TrailO Championships (PreO) on the same weekend, same venue

Wawel Cup, Poland, July (PreO)

Swedish O-Ringen, July (5 x PreO)

Scottish 6-Days, July-August (PreO)

Hungaria Cup, August (4 x PreO)

Cerkno Cup, Slovenia, August (PreO)

White Rose Weekend, August (PreO)