The 2009–10 season was Newport County's sixth consecutive season in the Conference South and they had been ever-present since the introduction of the Conference North & South in 2004.
Newport County attained promotion to the Conference National for the 2010–11 season on 15 March 2010 with seven league games remaining following a 2–0 victory over Havant & Waterlooville. In doing so County became the first team in the English football pyramid system to be promoted in the 2009–10 season.
The season began with optimism that the unbeaten run at the end of the previous season could be maintained. Former manager Tim Harris returned to the club on 7 May as General Manager citing "unfinished business".
The season began with a win and three draws, County finding themselves in 11th position, although with the unbeaten run from the previous season intact. The next five consecutive games were won, with County briefly going top of the table on 5 September although they were knocked off when Dover Athletic won an extra mid-week game. The chance to return to the top on the 16th was surprisingly missed when County could only draw with bottom-placed Weymouth despite taking the lead in the second minute. The next three games were won however, with County going top on 3 October.
The 20-match unbeaten run finally came to an end against mid-table Staines Town on 27 October. Staines won the game 1–0 although County goalkeeper Glyn Thompson spurned the chance to equalise when his last-minute header came back off the post! As second-placed Dover had also lost, County maintained their top spot.
Of the next 18 games, 15 were won and only three drawn, with County extending their lead at the top of the table.
Moving into March 2010, with 32 games played and County already 24 points clear of then second-placed Chelmsford City the winning post came into view. With 79 points in the bag, the most any of the chasing pack could achieve was 85. Newport travelled to bottom-placed Weymouth and duly recorded a 3–1 win. With Chelmsford also winning, the target was still 86. This set up the Friday and Monday games of the 12 and 15 March as the potential championship-winning games. A minimum of four points from those two games would have been enough to see County mathematically promoted to the Conference National irrespective of other results.
A then-record Newport Stadium league crowd witnessed a County victory in the Bishop's Stortford game, setting up the Havant & Waterlooville game as the decider. Despite only needing a point to seal the championship, that game was also won in front of new record crowd, sealing promotion in emphatic style.
The following match away to Thurrock, County suffered only their second defeat of the season, despite again taking an early lead. The next three games were won however before Havant & Waterlooville inflicted revenge for their 2–0 defeat in the championship-winning game by thumping County 4–0, their worst defeat since Bath City won by the same scoreline over a year previously!
The Conference South trophy was to be presented at the final home game against Dover Athletic. Early on in the season this was thought to be the potential championship-deciding match, but instead it turned into a victory parade for County. Another bumper crowd witnessed a 3–0 victory, finishing off the home season unbeaten and taking the team to the 100-point mark.
Although there was nothing for County to play for, the game away at Braintree Town was pivotal to the home side's chances of securing a spot in the play-offs. Going into the game a draw would have been enough to maintain fifth place for the home side, but their play-off hopes were effectively over after just eleven minutes. Two early goals for County seemed to have wrapped the game up, but a controversial penalty decision in the 54th minute saw Braintree back in the game and playing the last half an hour against ten men. County held on for a 2–1 victory though to deny Braintree a play-off spot and become the most successful team in the Football Conference's 31-year history.