Scottish international goalkeeper Paul Gallacher signed for Norwich on 2nd June 2004 on a free transfer from Dundee United where he was out of contract. He signed a two year contract with the option of an additional year and will be challenging Robert Green for the first choice keeper's position. Paul is Norwich's third full Scottish international in the squad after Gary Holt and Malky Mackay, both of whom helped sell Norfolk to Gallacher.

Lacking in match practice due to Robert Green's form in the first team and Darren Ward's occupation of the reserve team keeper role, Nigel Worthington revealed that he would be willing to let Paul go out on loan to get first team action, albeit on a clause that he could be recalled at 24 hours notice.

In early December 2004, he joined Gillingham on loan, making his debut in a 2-0 defeat to Wigan. He was recalled early from this loan on December 27th when Darren Ward was injured leaving Robert Green with only young Joe Lewis as cover. Paul was loaned out again on 18th March 2005, joining former manager Paul Sturrock at Sheffield Wednesday for a month. This was extended until the end of the season

In June 2005, speculation linked Paul with a return to Dundee United.

Paul made his debut for Norwich on 15th April 2005 in a 1-0 defeat at Sheffield Wednesday following an injury to Robert Green during the pre-match warm-up. He kept his place for the 3-2 win against QPR two days later and the 1-0 win at Cardiff the following Saturday. Although out of contract, Norwich offered him the opportunity to stay at Carrow Road for another season as Darren Ward was leaving the club. Former club Dundee United and Scottish side Dunfermline have also been linked with signing him. He was then linked with Aberdeen on 29th April 2006. In the end, he signed a new two year contract on 12th June 2006 and vowed to be Norwich first choice keper, aided by the fact that Robert Green is injured.

Although first choice keeper following Green's transfer to West Ham United, Gallacher faced the indignity of being replaced by loan signings (Jamie Ashdown, Lee Camp, David Marshall and Tony Warner) during the 2006/7 season. There was in May 2007 speculation that Hibs would seek to bring Gallacher back to Scotland. On 16th May, reports from Scotland said that Rangers' manager Walter Smith was looking to add Gallacher to the Rangers' squad. Smith is looking for experienced cover for first choice Allan McGregor, with 35-year-old German 'keeper Stefan Klos retiring and reserve team prospect Lee Robinson going out on loan. City boss Peter Grant said “I haven't had any contact from Rangers, but I wouldn't be surprised if they were interested because of the Scottish connection.”

On 23rd July 2007, Gallacher and Lewis were linked with a loan move to Brighton following Paul Crichton's appointment as a coach with the Seagulls. On 17th August 2007, Paul joined Scottish side Dunfermline on loan until 2nd January 2008.

Paul's contract with the Canaries was cancelled by mutual consent on 31st December 2007. The following day, he signed for Dunfermline until the end of the season. "I have enjoyed playing first team football at Dunfermline and everyone at the club has made me feel welcome. Dunfermline is a great club with a large fan base."

Paul signed for St Mirren (nicknamed The Buddies), his hometown club, on 29th June 2009 on a two year contract. "I'm obviously a local boy as I went to school here in Paisley so I obviously know a lot about St Mirren by living in the area, it is a great club to be a part of."

Out of contract at the end of the 2010/11 season, Paul was linked with a move back to Dunfermline while SPL rivals St Johnstone are also thought to be among his admirers. However Gallacher said "“I’d like to stay at St Mirren because I’m fairly settled there but football is so uncertain at the moment and you have to look at other options.“Yes, there is interest from other clubs, so we’ll just have to wait and see what happens. A lot of clubs are cutting back their budgets, so it makes sense to look at all the options that are on the table.”

Gallacher re-signed for Dunfermline on a two year deal on 9th June 2011

When Dunfermline went into interim administration on 28th March 2013, eight of their highest earning players were made redundant including Gallacher. He then signed for Ross County until the end of the 2012/13 season. County’s interest was natural given the severity of the hand injury ruling Mark Brown out for the rest of the campaign. Gallacher will now fight it out with Michael Fraser for the number one jersey.

Earning an honest wage for the last six months has been impossible with the Pars perilously close to liquidation. Trouble kicked off last October when the players first discovered they hadn’t been paid. Initially, they were told the problem would all be resolved within a couple of months. After six months of struggling and waiting for their dues, though, administration brought a raft of redundancies. None of the expunged players know if they will receive their money. Gallacher is just glad to be shot of it all.

The seven-times capped keeper told the Ross-shire Journal: “The situation at Dunfermline has been really hard to deal with. It is good to get away from the problems, but the club itself is a great one, steeped in history. It was fantastic to be involved in that and play there, but the past six months of part or non-payment of wages has been really difficult. So to get myself to a club of this standard and stature – one that is on the up – is fantastic. I feel lucky to be here. The boys have done fantastically well this year, securing the top-six spot with a game to spare.That’s testament to the hard work and ethic they have here and to the management team who have obviously worked really hard with them over the years.”

On 31st May 2013, Gallacher signed for Scottish Premier League newboys Partick Thistle. The 33-year-old has signed a one-year deal with the option of a further year, and will also take on the role of goalkeeper coach.

On 16th June 2016, Gallacher joined Hearts as player-coach after rejecting a new deal from Partick. He signed a two year contract with the Tynecastle side. He takes over coaching duties from Neil Alexander, who  joined Aberdeen.