A Northern Ireland under-21 international, he began his career at Derry City, making his first-team debut in May 2016. He was sold to English club Bristol City in August 2017, and from there he was loaned out to Barrow and Rochdale in the 2018–19 season. He spent the 2019–20 campaign on loan at Walsall and joined the club permanently in August 2020. However, four months later, he got a long-term knee injury and missed much of the 2020–21 season and the 2021–22 campaign. He spent the 2022–23 season with Port Vale before joining Cymru Premier club The New Saints in July 2023. He won the Cymru Premier and Welsh League Cup in the 2023–24 season.
On 30 August 2017, Holden signed with English Championship club Bristol City after a successful trial spell.[9][10] He had impressed manager Lee Johnson in two trials and the "Robins" agreed to a transfer-deadline day deal worth up to €300,000.[11] However, he never played a first-team game at Ashton Gate.[3]
He joined Barrow on a one-month loan, starting on 14 September 2018.[12] He played five National League games for Ian Evatt's "Bluebirds".[13] He joined League Two club Rochdale on loan for the rest of the 2018–19 season on 3 January 2019.[14] Manager Keith Hill said that "it's important we get players in who have the right mentality and who have the right game brain and intelligent energy, and Rory fits the bill".[15] He played seven matches for Rochdale.[13] He signed a new two-year contract with City in June 2019, with the club retaining a further 12-month option.[16]
Walsall
On 26 July 2019, he joined League Two club Walsall on a season-long loan following a trial period.[17] He made 36 appearances in the 2019–20 season, and though he played in a variety of positions he particularly impressed in an advanced midfield role.[18] He scored his first goal in English football on 15 February 2020, with his 93rd-minute strike securing a 3–2 victory over Northampton Town at the Bescot Stadium.[19]
On 11 August 2020, he re-joined Walsall on a permanent deal for an undisclosed fee.[20] He made a good start to the 2020–21 season, playing on the right-wing and equalling his season-high goals tally of two by mid-October as the "Saddlers" put together a 12-game unbeaten run in the league.[21] However, he suffered a knee injury before a game at Salford City in December 2020, and though he made a brief return to action the following April in which he was described as a "a breath of fresh air" by interim head coachBrian Dutton, he would then suffer a further setback and was ruled out for the entirety of the 2021–22 campaign, with head coach Matt Taylor stating that he had to undergo another procedure after seeing "the best knee specialist in the country".[22][23] He left Walsall upon the expiry of his contract in June 2022.[24]
Port Vale
In June 2022, he began training with League One side Port Vale, who were managed by Darrell Clarke, Holden's former boss at Walsall.[25] The club reportedly offered to pay his medical costs as he continued his recovery from long-term absence.[26] Holden signed for Port Vale on 29 July 2022.[27] He made his debut for the club the following day, though dropped out of the team in mid-August and missed some weeks of the season due to a "minor setback" of an injury.[28] He recovered and contributed with an assist during a 2–1 win over Barnsley in the EFL Trophy Round of 32 on 23 November.[29]David Flitcroft, the club's director of football, confirmed that the player's contract would not be renewed beyond June 2023.[30]
