Silicon On Insulator‐based devices seem to be the best candidates for the ultimate integration of Integrated Circuits on silicon. An overview of the main
SOI
materials and advantages of
SOI
for the Nanoelectronics of the next decades is presented. Nanoscale
CMOS
, emerging and beyond‐
CMOS
nanodevices, based on innovative concepts, technologies and device architectures, are addressed. The flexibility of the
SOI
structure and the possibility to realize new architectures allow to obtain optimum electrical properties for both low power and high performance circuits. These transistors are also very interesting for high frequency and memory applications. The performance and physical mechanisms are investigated in single‐ and multi‐gate/multi‐channel inversion‐ or accumulation‐mode thin film
MOSFETs
, realized on various semiconductors (Si, Ge,
III
‐
V
,
CNT
), down to sub‐10 nm gate length. The impact of strains in the channel and of high k materials is discussed. The interest of advanced emerging and beyond‐
CMOS
nanodevices on
SOI
for long term applications, based on nanowires or small slope switch structures is also highlighted. The influence of key device parameters on electrical and thermal floating body effects, short channel and quantum effects, noise, variability, as well as on hot carrier effects, versus temperature, is shown for various device architectures.