We have two different datasets that may fit your need: Gridded Population of the World (GPW), Version 4 and Global Rural-Urban Mapping Project (GRUMP). These are accessible at http://sedac.ciesin.columbia.edu/data/collection/gpw-v4 and http://sedac.ciesin.columbia.edu/data/collection/grump-v1, respectively.

The purpose of the GPWv4 project is to provide a spatially disaggregated population layer that is compatible with datasets from social, economic, and earth science fields.  The population data estimates, are provided for the years 2000, 2005, 2015 and 2020. The output is unique in that the distribution of human population is converted from national or subnational spatial units (usually administrative units) of varying resolutions, to a series of geo-referenced quadrilateral grids at a resolution of 30 arc seconds.

The Global Rural-Urban Mapping Project (GRUMP) adds rural-urban specification to an earlier (v3) version of GPW. The central data product resulting from GRUMP is a Gridded Population of the World with Urban Reallocation in which spatial and population data of both administrative units and urban extents are gridded at a resolution of 30 arc-seconds.  Additional data sets resulting from GRUMP include a 30 arc-second land area grid showing urban areal extents worldwide, and a database of human settlements, their spatial coordinates, and populations.