Elections to Brentwood Council were held on 6 May 1999. One third of the council was up for election and the Liberal Democrat party kept overall control of the council.
After the election, the composition of the council was
| Party | Seats | Gains | Losses | Net gain/loss | Seats % | Votes % | Votes | +/− | |
|---|---|---|---|---|---|---|---|---|---|
| Liberal Democrats | 9 | +1 | 64.3 | ||||||
| Conservative | 4 | -2 | 28.6 | ||||||
| Independent | 1 | +1 | 7.1 | ||||||
