A list of the most noteworthy RuneScape updates and events in 2005:
- 26 January - Slayer was released.
- Jagex began updating graphics in the free world.
- 21 March - The 2005 Easter event occurred for about two weeks. Rubber chickens were given as a reward.
- 4 April - Behind the Scenes - April
- 8 April - The RuneScape Wiki is created.
- 18 April - Desert Treasure and its reward, the Ancient Magicks spellbook, were released.
- 6 June - Behind the Scenes - June
- 6 June - Seeds and farming tools were released.
- 13 June - Tiaras, combination runes, and the Abyss were released.
- 5 July - Behind the Scenes - July
- 9 July - First player reaches maximum skill total.
- 11 July - Farming skill released.
- 8 August - Behind the Scenes - August
- 22 August - Return of the Letters page
- 25 August - The Hiscores were changed to show the top 500,000 players in each skill, versus the top 100,000.
- 5 September - Behind the Scenes - September
- 12 September - Cook-X was added.
- 19 September - Bank PINs were introduced.
- 26 September - New readers letters becomes the first issue of Postbag from the Hedge
- 26 September - The Mouse toy was released.
- 4 October - Behind the Scenes - October
- 4 October - TzHaar Fight Cave was added.
- 17 October - Mourning's Ends Part II was released.
- 31 October - 2005 Hallowe'en event, (31 October through 7 November).
- 5 December - Behind the Scenes - December, Tool leprechauns were added to the game, Spirits of the Elid was released, along with Nardah
- 12 December - Champions' Challenge is released, Skeletal Wyverns were added to the game
- 19 December - 2005 Christmas event, (19 December through 4 January 2006); Devious Minds was released