The 1990 North Hertfordshire District Council election was held on 3 May 1990, at the same time as other local elections across England and Scotland. There were 16 out of 50 seats on North Hertfordshire District Council up for election, being the usual third of the council.
Labour took most votes, gaining two extra seats. The Conservatives also gained a seat, increasing their majority on the council. The continuing Social Democratic Party lost every seat it was defending, leaving it with just one seat on the council. With poor results across the country the party disbanded shortly after the election. The one remaining SDP councillor in North Hertfordshire was Tony Quinn, whose term ran until 1991; following the demise of his party he joined Labour for the remainder of his term.
Overall results
The overall results were as follows:
Ward results
The results for each ward were as follows. An asterisk(*) indicates a sitting councillor standing for re-election.
Letchworth South East had previously been held by SDP councillor Geoff Williams, although the seat had been vacant since his resignation in November 1989.