The sub-floor brace for abating squeaking floors is a structural element that is configured for use with a supported flooring. The sub-floor brace for abating squeaking floors supports the supported flooring from the ceiling side of the supported flooring. The sub-floor brace for abating squeaking floors supplements the load carrying capacity of the joists that are supporting the supported flooring by creating a load path from the supported flooring to a supporting flooring located in an inferior location to the supported flooring. The supplemental load paths created by the sub-floor brace for abating squeaking floors reduce the squeaking noise commonly associated with aging floors. The sub-floor brace for abating squeaking floors is a telescopic structure that comprises a first support, a second support, and a fastener. The fastener attaches the first support to the second support.