Overview: The Spitzer Survey of Stellar Structure in Galaxies (S4G) is a volume-, magnitude-, and size-limited (d < 40 Mpc, |b|> 30°, m_Bcorr < 15.5, and D_25 > 1) sample of 2,352 galaxies, which have been mapped with IRAC channels 1 and 2 (3.6 and 4.5 microns). A follow-up survey added 465 early-type galaxies, bringing the total to 2,817 galaxies. This large, unbiased, and extremely deep sample of all Hubble types from dwarfs to spirals to ellipticals allows for detailed structural studies, not only as a function of stellar mass, but also as a function of the local environment. An extension of visible light images of 425 additional gas-poor late-type galaxies is currently being incorporated into the sample.