This letter proposes an adaptive all-pass filter (A2PF) based peak-to-average power ratio (PAPR) reduction scheme for signle input single output orthogonal frequency division multiplexing (OFDM) systems. A properly phase rotated OFDM symbol of reduced PAPR is generated by an A2PF with its filter coefficient found by the Newton-Raphson method. For the A2PF scheme, costly side information (SI) transmission is not needed unlike the selected mapping (SLM) scheme. The A2PF scheme achieves PAPR reduction performance comparable to the SLM scheme. Simulation results demonstrate that the A2PF scheme without SI leads to BER performance close to the SLM scheme with SI.