The following table shows all House of Assembly electorates to be contested at the 2018 state election, ordered according to two-party-preferred margin.
| Labor Seats | Liberal Seats | ||
| Seat | Margin | Seat | Margin |
| King | ALP 1.4% | Newland | LIB 0.1% |
| Hurtle Vale | ALP 1.7% | Adelaide | LIB 2% |
| Lee | ALP 2.6% | Black | LIB 2.6% |
| Torrens | ALP 2.6% | Gibson | LIB 3.2% |
| Light | ALP 3.9% | Mawson | LIB 3.2% |
| Badcoe | ALP 4.2% | Hartley | LIB 3.3% |
| Wright | ALP 4.5% | Colton | LIB 3.7% |
| Giles | ALP 5.7% | Dunstan | LIB 3.9% |
| Enfield | ALP 6.2% | Elder | LIB 4.3% |
| Kaurna | ALP 8.4% | Mount Gambier | LIB vs IND 7.2% |
| Taylor | ALP 8.8% | Morphett | LIB 7.7% |
| Florey | ALP 9.2% | Davenport | LIB 8.9% |
| Reynell | ALP 9.8% | Unley | LIB 9.2% |
| Elizabeth | ALP 9.9% | Waite | LIB 10.4% |
| Playford | ALP 11.5% | Morialta | LIB 11.6% |
| West Torrens | ALP 12.2% | Schubert | LIB 12.4% |
| Port Adelaide | ALP 12.5% | Heysen | LIB 13.2% |
| Cheltenham | ALP 14.4% | Finniss | LIB 13.7% |
| Ramsay | ALP 17.4% | Narungga | LIB 13.8% |
| Croydon | ALP 19.6% | Kavel | LIB 14.1% |
| Hammond | LIB 16.3% | ||
| Bragg | LIB 16.6% | ||
| Stuart | LIB 20.1% | ||
| Chaffey | LIB 24.4% | ||
| MacKillop | LIB 26.7% | ||
| Frome | IND vs LIB 9.5% | Flinders | LIB 28.7% |