This study considers robust time-of-arrival (TOA) source localisation algorithms. Range measurements are used to estimate the location parameter for TOA source localisation and previous information on the position of the source is employed to improve the existing measurement-based method. The proposed methods are categorised into two types. First, the mean square error between the true parameter and estimate is minimised. Second, the cost function where the penalty function is combined with the squared error function between the measurement and estimate is minimised. The positioning accuracy of the proposed algorithm is much higher than that of the conventional methods in regimes of large noise variances.