The 1888–89 FAW Welsh Cup was the 12th edition of the annual knockout tournament for competitive football teams in Wales. The competition was won by Bangor.
First round
Group One
| Home team | Score | Away team | Additional information | 
|  | 
|  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Group Two
| Home team | Score | Away team | Additional information | 
|  | 
| 
| Oswestry !Oswestry | 1 – 0 | Newtown RWW !Newtown RWW |  |  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Group Three
| Home team | Score | Away team | Additional information | 
| 
| Llangollen !Llangollen | 5 – 4 | Alyn White Star !Alyn White Star |  |  | 
|  | 
| 
| Rhostyllen Victoria !Rhostyllen Victoria | 8 – 1 | Corwen !Corwen |  |  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Vale of Llangollen receive a bye to the next round
Replay
| Home team | Score | Away team | Additional information | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Group Four
| Home team | Score | Away team | Additional information | 
|  | 
|  | 
| 
| Chester St Oswalds !Chester St Oswalds | 5 – 1 | Crewe Athletic !Crewe Athletic |  |  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Davenham receive a bye to the next round
Second round
| Home team | Score | Away team | Additional information | 
|  | 
|  | 
| 
| Wrexham !Wrexham | 4 – 12 | Alyn White Star !Alyn White Star |  |  | 
| 
| Rhostyllen Victoria !Rhostyllen Victoria | 3 – 3 | Vale of Llangollen !Vale of Llangollen |  |  | 
|  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Bangor receive a bye to the next round
1 Match protested regarding poor light, re-play was organised
2 Match protested regarding ineligible man, re-play was organised
Replay
| Home team | Score | Away team | Additional information | 
|  | 
| 
| Wrexham !Wrexham | 3 – 0 | Alyn White Star !Alyn White Star |  |  | 
| 
| Rhostyllen Victoria !Rhostyllen Victoria | 2 – 1 | Vale of Llangollen !Vale of Llangollen |  |  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
1 match abandoned after poor light
Second Replay
| Home team | Score | Away team | Additional information | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Third round
| Home team | Score | Away team | Additional information | 
|  | 
| 
| Wrexham !Wrexham | 1 – 01 | Rhostyllen Victoria !Rhostyllen Victoria |  |  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Chirk AAA receive bye to next round
1 match protested, re-play was organised
Replay
| Home team | Score | Away team | Additional information | 
| 
| Wrexham !Wrexham | 4 – 0 | Rhostyllen Victoria !Rhostyllen Victoria |  |  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Semi Final
| Home team | Score | Away team | Additional information | 
| 
| Hewitt  P leary(o.g)
  |  | D Lewis  P Leary
  40' W Lewis
  | 
| Stadium | Faulkner Street Chester
 |  
| Attendance | 2,000 |  |  | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
Replay
| Home team | Score | Away team | Additional information | 
|  | 
Source: Welsh Football Data Archive
a.e.t. = after extra time; agg. = aggregation score; pen. = decision by penalties.
.
Final
References
- ↑  The History of the Welsh Cup 1877-1993 by Ian Garland (1991) ISBN 1-872424-37-6
- ↑  Northwich Victoria - Historical Football Kits
|  | 
|---|
|  | 
|  | 
|  | 
| Domestic leagues |  | 
|---|
|  | 
| Domestic cups |  | 
|---|