Norwich City's academy announced on 18th August 2005 that goalkeeper Steve Arnold would be joining the Canaries as an Academy Scholar. Spotted by Academy youth scout Terry Harvey, Steve played at Colney in the Summer 2005 friendly against Rushden and obviously impressed the Academy team. Steve had previoulsy played for Boreham Wood and had spent six months with Arsenal's Under-15s side. It gave Steve great delight to keep a clean sheet for the Canaries when they visited Arsenal in an Under-18s clash in April 2006, watched by Arsene Wenger.

Arnold, who was on the bench for City's Carling Cup clash with Rotherham in the autumn of 2006, was awarded his first professional contract with Norwich on 11th May 2007.

Despite appearing on the City bench on 11 occasions during 2007/8, Steve was one of nine players released in May 2008 = primarily due to the emerging form of Declan Rudd and Jed Steer.

Steve signed for Grays Athletic in June 2008

Steve switched to Eastleigh in November 2009, after trialling with Brentford. He later had trials with Wycombe and signed for them on 21st January 2010

On 5th August 2011, he was loaned to Hayes and Yeading for one month. This was extended for the whole season with Arnold making 31 appearances.

Arnold was released by Wycombe on 9th May 2012. On 25th May 2012, he signed a one year contract with Stevenage.

Arnold was released by Stevenage on 17th May 2014. He then signed a two year contract with Forest Green Rovers on 6th June 2014. Arnold's first season at the New Lawn was blighted by injury and he finally made his debut in February 2015 and he went on the make fourteen appearance that season, including the play-off semi-finals against Bristol Rovers. Despite another injury-marred start to his second campaign, the 26-year-old made forty-five appearances in all competitions, including forty-three in the league, over a two-year spell at The New Lawn – he kept sixteen clean sheets.

On 17th July 2016, it was announced that Arnold had signed for Conference rivals Dover Athletic.

After making 30 appearances, including nine sheets, for Dover in 2016/17, he signed for Gillingham on 17th August 2017 on a one year contract, reuniting with former Forest Green manager Adrian Pennock. After failing to break into the Gillingham first team, his contract was mutually termintaed on 18th January 2018 and he signed for Barrow, managed by Pennock..

Released at the end of the 2017/18 season despite having made 17 appearances, Arnold then signed a two year contract with Shrewsbury on 19th July 2018.

On 5th June 2019, Steve transferred to Northampton for an undisclosed fee, signing a two year contract. He had played 32 games for the Shrews. Although he made just 10 appearances in 2019/20, three of them were in the League rTwo play-offs which saw Northampton defeat Cheltenham 3-2in the semi-finals before demolishing Exeter 4-0 at Wembley on 29th June 2020.

Northampton were relegated from League One on 1st May 2021. He was then released by the Cobblers on 12th May 2021. He had played 22 games for Northampton.

He signed for Southend on 2nd July 2021.

After being released by Southend at the end of the 2022/23 season, he signed for League Two side Sutton United on 16th June 2023 along with defender Omar Sowunmi and midfielder Christian N'Guessan. "Steve's someone we know well, as I worked with him early in my career as an assistant manager at Eastleigh" said Sutton manager Matt Gray. He had played 53 games for Southend.

Arnold was in the Sutton goal when they drew 4-4 with MK Dons on 27th April 2024. Combined with Colchester's draw, this meant Sutton returned to the National League. Arnold had played 18 games for Sutton.