In the 1906/07 season Hatfield FC merged with Dagmar House School Old Boys to form Hatfield United FC. The merger was driven by there being only one pitch available, namely Showfield, later known as Stonecross Road, as the other was taken up by the extension of the town cemetery.

The club began their league campaigns in the Mid Herts League in the 1890s and then moved to the Herts County League. In the 1920s there was another merger, this time with Hatfield Cricket and Athletic Clubs to form Hatfield United Athletic Club.

Moving up to the senior amateur Spartan League, their first season was cut short by the outbreak of war and they managed to complete only one fixture. The club reformed after the war and three years later the merger with the cricket section was undone with the cricketers returning to Hatfield Park and the football section continuing to compete in the Spartan League as Hatfield Town FC.

After several seasons they were not re-elected and moved to the Parthenon and London League before entering the Metropolitan League in the mid 1960s as a semi-professional club with a number of permit players on their books. In the late 1970s when, once again, finances were inadequate the limited company was wound up in the High Court.

The football club continued to play at Stonecross Road until 1980 when the land was sold for housing, forcing a move to Angerland Common until 1984 when the club folded due to lack of finances and a committee to run the club.

Reforming in 1989 Hatfield Town played on the council run Roe Hill Playing Fields pitch and entered the Herts Senior County League where they won three divisional championships in successive seasons. Promotion to the South Midlands League prompted a move to Gosling Sports Park in neighbouring Welwyn Garden City before yet another collapse into dissolution in 1996. The club reformed once again in 1999, re-joining the Herts Senior County League.

Ahead of the 2007/08 season and with a change in management personnel, the club experienced an influx of players and hence a third team was registered that will play their home games at Roe Hill Playing Fields.

The end of the 2007/08 season saw the club promoted back into the Spartan South Midlands League after winning both the Herts Senior County Premier Division and the Reserve Division One. What was the A Team for the 2007/08 campaign went on to become a splinter group who formed AFC Hatfield and who aim to keep the Hatfield flag flying in the Herts Senior County League.

The 2008/09 season saw Royston Town run away with the Division One championship. Four clubs battled hard for the runners-up spot, amongst them Hatfield Town, who exceeded all expectations in their first season back in the Spartan South Midlands League. As the season drew to a close disappointment struck twice when firstly Town lost the Herts Senior Centenary Trophy Final, going down to Hoddesdon Town in a penalty shoot-out after goalkeeper Sam Lacey had been carried off with a nasty gash to his leg and unable to continue; and then secondly as Kings Langley nabbed the runners-up spoils in a tense last month of fixtures. Town lost a "six pointer" at Kings Langley 0-2 late in the campaign which all but gifted the West Herts club second place. Luck did turn in the close-season though as Kings Langley's ground wasn't up to the standard required, third placed Hatfield Town gratefully accepted the offer of promotion.

In 2010 Hatfield Town made a semi-permanent move to the Gosling Sports Stadium in Welwyn Garden City. Much work was required to bring the ground up to the sufficient standard, but the opportunity to have their own ground more than compensated the effort.

Hatfield cemented their position in the Premier Division during the 2009/10 season finishing a creditable 12th in the league table. However, during the 2010/11 season Hatfield were to see many changes in the coaching staff. First Trevor Lloyd, long time manager of Hatfield Town, chose to take time out of football. His replacement, Andy Prutton, was to last only a few months at the helm before deciding to ply his trade elsewhere. Adam Parker was to step in, and despite some attractive football being played, the results were not good enough for Adam to want to remain at the club, and towards the end of the season he decided to leave. Regardless of the managerial changes, Hatfield still managed to improve their league position with an 11th placed finish, and the reserve team beat London Lions 3 – 1 to win the challenge trophy final.

For the 2011/12 season the club appointed joint managers Darryn Stewart and Kevin Pearman to take on the challenge. The season started successfully, with the club reaching the second qualifying round of the FA Cup, equalling the furthest the club has ever achieved in the competition. During the season the Chairmanship was to change twice, with current Chairman Chris Maloney stepping in to the position towards the end of the season. Despite the success in the cup, the team slowly started to slip down the table, and even after tinkering with the management team Hatfield finished bottom of the league and were relegated. However, due to events elsewhere, the club was invited to remain in the premier division which they gladly accepted.

After a brief stint as manager, Mike Hollister left the club and Micky Nathan took over as manager of the first team for the 2012/13 season. Many youth teams joined the club, including a disabled team. Chris Maloney aims to make the club a credit to the town it represents and a positive influence on the youth of Hatfield.
Hatfield Town are an ambitious club whose plans for the future include the building of their own ground and advancement within the pyramid.