The large polyamory meetings that are held in English:

Open Con Catalonia:  Every last weekend in May, that is  26. – 28. May 2017 (venue is 130 km from Barcelona, between Girona and Figueres) – held in English

2. Non-Monogamies and Contemporary Intimacies Conference: 31.08. – 02.09.2017 – Vienna, Austria

OpenCon UK did not happen in 2015 and 2016 – in Gillingham (Dorset) – check the site for news.

Local meetings:

*Danmark:
Lokale poly-grupper

*France:
http://polyamour.info/evenements/-fr-/

*Germany:
PAN meetings (national german meetings):
Wintertreffen: Fr. 24.02. – Di. 28.02.2017 im Gästehaus Rommerz bei Fulda
PAN Frühjahrstreffen: Mi. 14.06. – So. 18.06.2017,  Am Windberg e.V. in Thüringen
PAN Herbsttreffen:  Fr. 06.10. – Di. 10.10.2017,  Gut Frohberg in Sachsen bei Meissen
Schlampenau/ flt*poly-Ferien: 13.-20. August 2017 in Zülpich
Local german meetings (über den Reiter Polytreffen -> DE)
List of meetings in german language

 *Greece:
On meetup, there is an Athens Polyamory Group

*Ireland:
On meetup, there is a Dublin Polyamory Discussion/Support Group

*Italy:
Eventi
OpenConItalia

*Slovakia:
Bratislava https://www.facebook.com/events/1242834265752986/

*Sweden:
PolyWeekend i Arvika

*Switzerland:
List of meetings in german language

*United Kingdom:
Polytical event calendar
London Polyamory Meetup Group