Just this morning it was announced that the 27-year old TV and radio star will be taking over from Chris Moyles on the BBC Radio 1 Breakfast Show.
The newly-promoted presenter, who hosted the event, was joined by friends Pixie Geldof, the Xtra Factor's Caroline Flack, fellow Radio 1 DJ and T4 presenter Jameela Jamil and Dutch singer and songwriter Esmée Denters.
Other guests included former Britain's Got Talent contestants Loveable Rogues and up-and-coming singer Jessie Ware, who later performed at the bash.
Let's hope that Grimshaw is good as a 'morning person' when the new job starts in September.
Copyright: Rex Features