| Country: | Northern Territory |
| Type: | parliamentary |
| Ongoing: | no |
| Election Date: | 31 July 1999 |
| Party1: | Australian Labor Party (Northern Territory Branch) |
| Popular Vote1: | 1,563 |
| Percentage1: | 53.6% |
| Swing1: | 1.6pp |
| Candidate2: | Maisie Austin |
| Party2: | Country Liberal Party |
| Popular Vote2: | 853 |
| Percentage2: | 29.2% |
| Swing2: | 18.7pp |
| Candidate3: | Carrie Altamurra |
| Party3: | Independent politician |
| Popular Vote3: | 417 |
| Percentage3: | 14.3% |
| Swing3: | 14.3pp |
| 2Blank: | TPP swing |
| 1Data1: | 63.5% |
| 2Data1: | 11.5pp |
| 1Data2: | 36.5% |
| 2Data2: | 11.5pp |
| MP | |
| Before Party: | Australian Labor Party (Northern Territory Branch) |
| After Party: | Australian Labor Party (Northern Territory Branch) |
A by-election for the seat of Wanguri in the Northern Territory Legislative Assembly was held on 31 July 1999. The by-election was triggered by the resignation of Labor (ALP) member John Bailey. The seat had been held by Bailey since winning a previous by-election in 1989.
The ALP selected Paul Henderson, a computer analyst, as its candidate. The CLP candidate was Maisie Austin.