The North Zone in the Ranji Trophy, 1965-66 saw the participation of a number of 6 teams, all from the Northern part of India. There was no change in the participating teams, as the teams that were participating in the previous editions, participated in the Ranji Trophy, 1965-66, as well. The teams included the likes of Northern Punjab, Southern Punjab, Delhi, Jammu & Kashmir, Services and Railways and all of them vied for a birth in the knock out level of the tournament. The teams like Delhi and Services eventually represented the North Zone in the knock out level.

The first of the North Zone league matches in the Ranji Trophy, 1965-66 was held between the teams of Northern Punjab and Jammu & Kashmir and the match was held at Jullundur from 01-03 December, 1965. The Northern Punjab team played well in the match and won it by a margin of an innings and 86 runs for earning 8 points from it. The next match of the zone involved the teams of Southern Punjab and Services and it was held at Patiala from 01-03 December, 1965. The Services team won the match by a margin of 150 runs and earned 8 points from the match. The Services team then played against the Northern Punjab team at Ludhiana from 05-07 December, 1965, where it won by a margin of 9 wickets for earning 8 valuable points.

The teams of Southern Punjab and Jammu & Kashmir played against each other in the fourth of the North Zone league matches in the Ranji Trophy, 1965-66 that was held at Patiala from 05-07 December, 1965. The Southern Punjab team clinched a victory of 151 runs in the match and earned 8 points from it. The next match saw a battle between the teams of Delhi and Jammu & Kashmir and the match took place at Delhi from 09-11 December, 1965. The winner of the match was the Delhi team with a huge margin of an innings and 51 runs and it earned 8 points from the match, as well. The sixth match of the North Zone involved the teams of Services and Jammu & Kashmir and the match was held at Delhi from 13-14 December 1965. The Services team continued its good for in this match also and earned 9 points from it by winning with a huge margin of an innings and 175 runs.

The match between the teams of Railways and Jammu & Kashmir was the seventh of the North Zone league matches in the Ranji Trophy, 1965-66, where the Railways team won by an innings and 173 runs. The match was held at Delhi from 17-18 December, 1965 and the Railways team also earned 9 points from the match. The teams of Southern Punjab and Northern Punjab then clashed with each other in the next match of the North Zone at Jullundar from 21-23 December, 1965. The match saw the Southern Punjab team winning by 167 runs and earning 8 points from it. The next match of the zone was played between the teams of Delhi and Railways at Delhi from 21-23 December, 1965. The match was drawn during the stipulated duration and the match officials awarded the Delhi and Railways teams 5 and 3 points, respectively for the match.

The tenth of the North Zone league matches in the Ranji Trophy, 1965-66 was played at Delhi from 25-27 December, 1965, between the teams of Services and Delhi. The drawn match saw the Services team earning 6 points and Delhi earning 3 points from it. The next match featured the teams of Railways and Northern Punjab, when the teams met with each other at Delhi from 25-27 December, 1965. The Railways team won the match convincingly by a margin of an innings and 14 runs to earn the entire 9 points from the match. The next match saw a clash between the teams of Railways and Northern Punjab at Delhi from 29-31 December, 1965, where the Railways team won by 7 wickets and earned 8 valuable points.

Then, the two teams of Services and Railways clashed with each other in the next match of the North Zone at Delhi from 02-04 January, 1966. The drawn match saw the Services team earning 5 points and Railways earning 3 points from it. The Delhi team then played against the Southern Punjab team at Chandigarh from 09-11 January, 1966 and the Southern Punjab and Delhi teams earned 5 and 3 points, respectively from the drawn match. The last of the North Zone league matches in the Ranji Trophy, 1965-66 was played between the teams of Northern Punjab and Delhi at Jullundur from 14-16 January, 1966. As the match was drawn, the match officials awarded the Delhi and Northern Punjab teams 5 and 3 points, respectively for the match.