The league featured twenty-one clubs, twenty of which competed in the previous season together with one additional club: •
Sheppey United, relegated from the
Southern League The league was won by
Sittingbourne, the only Kent League winning club (as of 2024) to be unbeaten over the season; it was their third Kent League title and they were subsequently promoted to the
Southern Football League. At the end of the season both bottom clubs, Metropolitan Police (Hayes) and
Sheppey United, were re-elected to continue their membership of the division.
League table Challenge Cup The 1990–91
Kent Football League Challenge Cup was won by
Faversham Town for the second occasion, their first being twenty seasons previously. The competition, contested by all twenty-one clubs in Division One, comprised five single match tie rounds (with the first round featuring five ties) culminating in the final which was played on a neutral ground (at
Whitstable Town F.C. this season).
Quarter-finals, Semi-finals and Final Second Round •
Ramsgate 2 – 1
Deal Town •
Darenth Heathside 3 – 2
Sittingbourne •
Alma Swanley 4 – 2
Whitstable Town •
Slade Green 2 – 1
Tonbridge •
Tunbridge Wells 6 – 0
Beckenham Town • Metropolitan Police (Hayes) 1 – 3
Chatham Town •
Faversham Town 6– 0
Thames Polytechnic •
Herne Bay 0 – 1
Danson First Round •
Ramsgate 4 – 0
Crockenhill •
Darenth Heathside 3 – 0
Cray Wanderers •
Alma Swanley 1 – 0 Kent Police • Replay:
Alma Swanley 3 – 1 Kent Police •
Herne Bay 3 – 0
Sheppey United •
Greenwich Borough 1 – 4
Danson • Byes for the other eleven clubs Sources: • Final: • Semi-finals: • Quarter-finals: ; • Second Round: ; • First Round: ; ==Reserves Section==