The club went on to win this division twice before the Second World war, but never achieved promotion to Division one.[4] During this time the club made its debut in the FA Cup in the 1928–29 season and the club won the Dorset Senior Cup on four occasions. After the second world war the club rejoined the Western football league for the 1946–47 season but this time were placed in Division one. The club then spent the next 24 seasons in this division, during which time they finished as Runners-up once and went on to win six more Dorset Senior Cup finals. The club then left the Western Laegue to join the Dorset Football Combination League for the start of the 1970–71 season.[5] The club then won the league at their first attempt. It would be another 28 seasons though the club would have to wait for another league title in the 1998–99 campaign , when they achieved the double by winning the league cup as well. They repeated this success the following season as well.
1994 saw the club move from their original home of Grove corner to New Grove Corner, when the Crown decided it needed the land for mineral extraction. After finishing as runners-up and with improvements made to their new ground the club joined the Wessex Football League for the start of the 2001–02 season. The club then remained in the Wessex league until the end of the 2005–06 season, when they dropped back into the Dorset Premier Football League. Since then the club won the league two times more, once in the 2007–08 season though they made the decision not to seek promotion, and again the following season. In the 2013–14 season the club became winners of the Dorset Premier League for the seventh time in their history. The Blues returned to the Wessex League Division 1 in 2015/16 season after an absence of nine years and winning it at the 1st time of asking whilst being promoted to the Premier Division. The following season 16/17 Portland United were Champions again as they lifted the Sydenhams Wessex League Premier Division title in their 1st season in the division despite still being an amateur side.
