Wales will host Bosnia-Herzegovina in the World Cup play-off semi-finals, while Scotland are at home to Austria.
A Wales victory would earn them a trip to face Switzerland in one of three play-off finals.
Should Scotland beat Austria, they will be at home again in a final, against the Republic of Ireland.
The play-offs will decide two automatic qualifiers for the 2023 World Cup plus one country who will play in inter-confederation play-offs.
Wales secured second place in their group with Tuesday’s 0-0 draw against Slovenia and are potentially two wins from their first ever World Cup finals.
Scotland were runners-up to Spain in Group B.
They prepared for the play-offs with a six-goal thrashing of the Faroe Islands in their final qualifier.
The two UK countries join seven other second-placed teams in the European play-offs.
The best three – Iceland, Republic of Ireland and Switzerland – go straight into one-legged play-off finals which take place on 11 October.
Wales and Scotland must win their one-legged semi-finals, which take place on 6 October, to reach their respective finals.
Portugal will host Belgium in the third semi-final, with the winners at home to Iceland in the final.
The two best-ranked final winners – based on performance in their qualifying groups and the play-off finals – will head to the World Cup, with the third victorious side going into the inter-confederation play-offs, which take place next February in New Zealand.
Those play-offs will feature 10 teams divided into three paths, with three World Cup spots on offer.
The third-ranked European play-off winner will play one of Chinese Taipei, Thailand, Cameroon, Senegal, Haiti, Panama, Chile, Paraguay and Papua New Guinea in a one-off final.
Scotland reached their first World Cup finals in 2019 but missed out on this summer’s European Championship after finishing behind Finland and Portugal in their qualifying group.
According to Fifa’s world rankings, Iceland, in 14th, are the strongest side involved in the European play-offs ahead of Belgium, who are 19th.
Austria are ranked 20th and Switzerland are 21st with Scotland, who are 23rd, coming next. The Republic of Ireland are ranked 26th, with Portugal 27th and Wales 30th, while Bosnia & Herzegovina are 63rd.
World Cup play-offs – how do they work?
- The nine teams which finished in second place in their qualifying groups are given a play-off spot.
- The play-offs consist of a semi-final and final, both single-legged ties.
- The matches will be played on Thursday, 6 October and Tuesday, 11 October.
- Based on performances in qualifying, the three top seeded teams – Iceland, Republic of Ireland and Switzerland – are given a bye to the final, while the remaining six teams will be entered into the semi-final draw.
- The three winning semi-finalists will play one of Iceland, Republic of Ireland or Switzerland in the final.
- From the three final winners, the two highest seeded teams will qualify for the 2023 Women’s World Cup.
- The third seeded side will be entered into an Inter-Confederation Play-Off, which will take place in New Zealand in February 2023.