Designing procedure of economical and safe side weirs that are used in various hydraulic structures such as intakes and deviation systems, essentially needs the ability to predict the side weirs' discharge capacity accurately. In this paper, the discharge coefficient of a modified labyrinth side weir was modeled by employing the support vector regression (SVR) method. To find the optimum SVR scenario, eight different kernel functions and six different input combinations were investigated. The accuracy of the SVR models were compared with two nonlinear regression equations from other published studies. The results showed that the SVR model with Polynomial Kernel Function and w=L; Fr 1 = sin h 0 ; w=Y 1 and w sin h 0 =Y 1 as input parameters performs better than other models in predicting the discharge coefficient. Where w, L, h 0 , and Y 1 are the height of crest, weir length, oblique side-weir included angle, and upstream flow depth, respectively. Also, the results showed that the SVR model with mean square error (RMSE) of 0.050 performs much better than the two other nonlinear regression published equations with RMSE of 0.121 and 0.4270, respectively.