The men's 800 metres at the 2007 World Championships in Athletics was held at the Nagai Stadium on 30, 31 August and 2 September.
Prior to the competition, the following records were as follows.
Qualification: First 3 in each heat(Q) and the next 6 fastest(q) advance to the semifinals.
Qualification: First 2 in each semifinal (Q) and the next 2 fastest (q) advance to the final.