Michael James Scott, who currently plays the same role in the US touring production of the show, will fill the sparkly boots at the Prince Edward Theatre between 17 August and 30 September.
Scott returns to the West End for the first time in eight years after performing in the Broadway transfer of Hair at the Gielgud Theatre in 2010. Before performing in the touring production of Aladdin, he was the standby Genie in the original Broadway production in 2014 and originated the role in the Australian production.
In a straight swap, Nicholas (who originated the West End role and won the WhatsOnStage Award for Best Supporting Actor in a Musical) will take on the role of Genie for a leg of the US tour while Scott performs in the West End.
Speaking of the announcement, Nicholas said: "Being presented with the chance to perform this phenomenal show as Genie in Pittsburgh is something I cannot pass up. In a city
so close to where I grew up, having an audience full of family and friends, is another dream
Earlier this year a new round of casting was announced for the West End production, which first opened in 2016.