The four Irish sides that have qualified for Europe will endure a nervier time than usual thanks to UEFA's new qualifier schedule.
All Champions League qualifiers prior to the playoff stage will be one-legged affairs.
UEFA's Executive Committee confirmed the news at a press conference in Nyon on Wednesday afternoon.
European football's governing body has confirmed that sides drawn out first in the qualifiers will have home advantage.
Such is the need to start the next season promptly, the preliminary and first qualifying rounds of the Champions League will be played before the current season's competition reaches its conclusion in Lisbon.
SSE Airtricity Premier Division champions Dundalk will enter the Champions League at the first qualifying round phase (August 18-19).
Shamrock Rovers, Bohemians and Derry City will all begin their Europa League campaign on August 27 in the first qualifying round.
Women's National League Champions Peamount United are set to begin their European campaign in the UEFA Women's Champions League qualifying round mini-tournaments, played between October 7 and 13.
The draw for the qualifying groups will take place in the first week of September.
Key dates:
UEFA Champions League 2020/21
Preliminary round: 8 and 11 August
First qualifying round: 18/19 August
Second qualifying round: 25/26 August
Third qualifying round: 15/16 September
Play-offs: 22/23 and 29/30 September
Group stage: 20/21 and 27/28 October, 3/4 and 24/25 November, 1/2 and 8/9 December
UEFA Europa League 2020/21
Preliminary round: 20 August
First qualifying round: 27 August
Second qualifying round: 17 September
Third qualifying round: 24 September
Play-offs: 1 October
Group stage: 22 and 29 October, 5 and 26 November, 3 and 10 December
UEFA Women's Champions League 2020/21
Qualifying round mini-tournament: 7 and 13 October