In the summer of 1997, Holland joined Ipswich Town for a fee of £800,000. He again became team captain and captained the club into the Premier League by winning the First Division play-offs in 2000. He captained the club to a fifth-place finish and qualification for the UEFA Cup in their first season in the Premier League in 2001. Though Ipswich were relegated in 2002 he stayed with the club after he turned down a £4.5 million move to Aston Villa. His spell at Ipswich is most remembered for the consistency he showed, after playing 223 consecutive games and only missing one league match (due to international duty) in the six years he was at Portman Road.
After Ipswich failed to win promotion in 2003, Holland moved back to the Premier League by joining Charlton Athletic on a four-year contract for an initial £750,000 fee, which later rose to £900,000. Again with this move he assumed the captain's armband and was ever-present in his first season for the club. One of the longest-serving Charlton players, he claimed more than half the entire vote for the 2007–08 Fans' Player of the Year. His final match came in a 2–2 draw with Cardiff on 21 April 2009, and the club released him after relegation to League One at the end of the season.
In July 2009, Holland trained with Colchester United following his release from Charlton in order to keep himself fit.
Although born in England, Holland qualified to play for the Republic of Ireland through his grandmother who hailed from County Monaghan. He made his international debut on 9 October 1999 in an away Euro 2000 qualifier against Macedonia, playing the last five minutes as a substitute for Mark Kennedy. His first goal came on his fifth cap, the equaliser in a 1–1 draw with Portugal on 7 October 2000 in qualification for the 2002 FIFA World Cup. Holland captained the side in three internationals, the first on his 28th cap, a 2–0 friendly defeat to Scotland.
He went with the Republic of Ireland to the 2002 World Cup scoring the equaliser against Cameroon in their opening game. Ireland were eliminated from this tournament in a Second Round penalty shoot-out against Spain, with Holland among those who missed. Following Ireland's failure to qualify for the 2006 World Cup, he announced his retirement from international football on 5 February 2006 having made 49 appearances and scoring five goals. Manager Steve Staunton had attempted to persuade Holland to continue.
He was one of several players and managers (including Danny Mills and Paul Jewell) who acted as summarisers for BBC Radio Five Live during the 2006 World Cup. Holland has also appeared on the BBC television program A Question of Sport and the radio quiz Fighting Talk. Holland as a freelance pundit has appeared on nearly every media outlet covering football in the UK. He has been a pundit on ESPN & Sky Sports, appeared on BBC results service Final Score on the odd Saturday afternoon and appeared on ITV commentating on the UEFA Cup. He is also a presenter for the Eastern England edition of the BBC regional football show Late Kick Off.
He has also appeared on many radio shows, he usually appears on talkSPORT on kick off usually on Thursday nights and also appearing on Matchday Live on Saturday afternoons whenever he is not on Final Score. Holland has also appeared frequently on Absolute Radio and BBC Radio 5 Live as a co-commentator as well as Final Score, Premier Soccer Saturday or talkSPORT. In addition Holland previously appeared as an analyst for Setanta Sports' live matches.
Holland began work with RTÉ when he commentated alongside George Hamilton during the Rep. of Ireland and Brazil friendly. He then appeared as a member of the panel on RTÉ's Premier Soccer Saturday for a number of weeks. He commentated the 2010 FIFA World Cup.