Wireless communications systems may support flexible waveform configuration for autonomous uplink transmissions. A base station may transmit broadcast signaling (e g , a system information block (SIB)) indicating waveform configuration information for an autonomous uplink transmission by a user equipment (UE). In some cases, the broadcast signaling may include a waveform configuration field (WCF) that may indicate whether flexible waveforms for autonomous uplink are supported, may configure a waveform type, may indicate waveform configuration mapping rules, etc. As such, a UE may identify whether flexible waveform configuration for autonomous uplink is supported, and may determine waveform types for autonomous uplink transmissions based on waveform type configuration information from a base station (e.g., which may include an indication of whether flexible waveform configuration is supported, an indication of waveform type/scenario mapping rules, etc.), one or more LUTs, identified autonomous uplink scenarios, autonomous uplink transmission parameters, or some combination thereof.