| Competition: | Nemzeti Bajnokság I |
| Season: | 1999–2000 |
| Winners: | Dunaferr |
| Relegated: | Siófok Diósgyőr Vác Szeged LC |
| Continentalcup1: | Champions League |
| Continentalcup1 Qualifiers: | Dunaferr |
| Continentalcup2: | UEFA Cup |
| Continentalcup2 Qualifiers: | MTK Budapest Vasas |
| Continentalcup3: | Intertoto Cup |
| Continentalcup3 Qualifiers: | Tatabánya |
| League Topscorer: | Attila Tököli (22) |
| Biggest Home Win: | Ferencváros 8–0 Vác |
| Biggest Away Win: | Vác 0–5 MTK Vác 0–5 Debrecen |
| Highest Scoring: | Ferencváros 8–0 Vác |
| Matches: | 289 |
| Total Goals: | 721 |
| Prevseason: | 1998–99 |
| Nextseason: | 2000–01 |
The 1999–2000 Nemzeti Bajnokság I, also known as NB I, was the 98th season of top-tier football in Hungary. The league was officially named Professzionális Nemzeti Bajnokság (PNB) for sponsorship reasons. The season started on 7 August 1999 and ended on 27 May 2000.
It was contested by 18 teams, and Dunaferr FC won the championship under coach Sándor Egervári. The team from Dunaújváros claimed their first ever national title. Dunaferr finished an astounding 15 points above runners-up and defending champions MTK and lost only one game throughout the entire campaign. Dunaújváros' Központi Sporttelep served as a true fortress, as the team went unbeaten at home for the entire season, and won all but one home ecounters, which was a 1-1 draw against MTK.
| Rank | Scorer | Club | Goals |
|---|---|---|---|
| 1 |  Attila Tököli | Dunaferr SE | 22 |
| 2 | Péter Horváth | Ferencvárosi TC | 19 |
| 3 | Mihály Tóth | Ferencvárosi TC | 18 |
| 4 | Gábor Zavadszky | Dunaferr SE | 14 |
| 5 | Béla Illés | MTK Hungária | 13 |
| Péter Kabát | Vasas SC | 13 | |
| Krisztián Kenesei | MTK Hungária | 13 | |
| 8 | Gyula Horváth | Nagykanizsai Olajbányász | 11 |
| Zoltán Kovács | Újpest FC | 11 | |
| Norbert Tóth | Újpest FC | 11 | |