Student Profile Pancasila is a character that characterizes Indonesian students. For this reason, the character values of Pancasila students should be instilled in schools from an early age. The purpose of this study was to construct a Pancasila student character instrument for elementary school students. This study uses a quantitative approach with a sample of 697 grade 3 and grade 4 students in Soppeng district. Data analysis in this study uses validity and reliability. Content validity using Aiken's V for 40 items succeeded in reducing the instrument to 35 items with a validity index at 0.76-1. CFA analysis to prove content validity shows that the model is fit with 24 items. The reliability estimation shows that a 24-items instrument is reliable. Thus it can be concluded that the 24 items of the Pancasila Student Profile instrument in construction terms can be used to measure the character of 21st century students in Indonesia. [For the full proceedings, see ED654100.]