The 2003 season would prove to be City's last with Le Coq Sportif, and it was all change at the outset of the next campaign, with Dublin sportswear firm O'Neills taking over as the kit manufacturer while Nissan replaced Guinness as the main shirt sponsor, though Guinness remained as a shorts sponsor along with Wallace, while local radio station RedFM joined the Evening Echo as a sleeve sponsor. The kits were not bad at all, O'Neills' home kit (left) not totally different from its Le Coq predecessor, though the shorts were now white while the socks were green.

On the pitch, changes came in the form of former Tottenham Hotspur and Republic of Ireland B striker Neale Fenn, who had been outstanding with Waterford United the
previous season, while left-back Danny Murphy (not that one) was also added by manager Dolan as he sought to continue the club's upward progression following fourth- and third-placed finishes over the previous two seasons. City began their league campaign with a 3-1 home win against Dublin City, with Fenn, John O'Flynn and George O'Callaghan scoring, but they suffered defeat in their first away game, going down 2-1 away to Shamrock Rovers. That game provided a first opportunity to wear the new away kit, with O'Neills opting to retain navy, which had been introduced the previous season (above right). While it wasn't a bad design, the decision to have red below the Nissan logo and not above it was curious, while the short-sleeved and long-sleeved versions had different details. The shorts and socks were the same designs as the home kit but with navy the dominant colour, the Wallace logo added after its first outing (right).
When the fourth game produced a 3-2 home defeat to Waterford, City were in the precarious position of only having won one from four, and while a 2-0 victory away to St Patrick's Athletic improved things, Shelbourne then came to Turner's Cross and triumphed by the same scoreline - thanks to two Dan Murray own goals - the Dublin side were five points clear at the top after only six games while City were a further four back in sixth place. They would remain undefeated in the league for the next 10 games, however, propelling them up to second even though Shels remained the favourites for the title. By now, the eircom League patches had been added to the shirts while the Wallace logo moved from the shorts to the back of the jerseys (below left), though as this picture shows, the two shorts styles were often worn in the same match.
Coming third in 2003 had meant that City were entered into the Intertoto Cup, where first Malmo and then NEC Nijmegen were defeated before Nantes ended City's odyssey. As usual, a home shirt with just one sponsor had to be used, while numbered shorts were again called upon (above right). Presumably a similar version of the away kit existed but it never saw the light of day as it was deemed to clash with Nijmegen's green, red and black home strip.

To solve the confusion, City wore an all-white kit belonging to local side SEC, with the the O'Neills logo applied as a patch over that of the actual maker, Trepo, while a plain football was the makeshift crest instead of SEC's (below left). As it was worn just once and never available to fans (though naturally Mick Ring has one), it is one of the rarest City kits ever, its only real rival the long-sleeved shirt from 1984-85.

Back at home after the European adventure ended, City found themselves with games to make up and while it took time to find their form again, they began to pick up real momentum as the end of the season neared, mid-season signing Joe Gamble settling in impressively. A to Bohemians on September 19 was their final defeat of the season but ultimately their 12-game unbeaten run was only good enough for second place, a 0-0 draw with Shels in October the key result as they stayed just ahead of City. It represented further progress though, and that would continue into 2005.