At the 2013 World Aquatics Championships in Barcelona, Lim finished 29th in the 50-metre freestyle in 25.86. In the relays, Lim with Lynette Lim, Mylene Ong and Quah Ting Wen finished 14th in the 4 × 100-metre freestyle in 3:48.85; the same foursome finished 12th in the 4 × 200-metre freestyle in 8:15.91 and Lim with Quah, Tao Li and Samantha Yeo finished 15th in the 4 × 100-metre medley in 4:10.69. At the first leg of the 2013 FINA Swimming World Cup in Eindhoven, Lim finished 18th in the 200-metre freestyle in 2:02.02, 19th in the 50-metre freestyle in 25.55, 19th in the 100-metre freestyle in 55.34 and 24th in the 50-metre butterfly in 29.37. At the second leg in Berlin, Lim finished 19th in the 50-metre freestyle in 25.46, 19th in the 100-metre freestyle in 55.41 and 20th in the 100-metre individual medley in 1:06.26. At the sixth leg in Singapore, Lim finished 11th in the 400-metre freestyle in 4:24.75, 14th in the 200-metre freestyle in 2:02.03, 18th in the 50-metre freestyle in 25.88 and 20th in the 100-metre freestyle in 56.98. In the mixed 4 × 50-metre medley relay, Lim with Quah Zheng Wen, Christopher Cheong and Tao Li finished 7th in 1:44.94 and in the mixed 4 × 50-metre freestyle relay, Lim with Darren Lim, Russell Ong and Mylene Ong finished 5th in 1:35.73. Lim closed out the year by winning four medals at the 2013 Southeast Asian Games in Naypyidaw, Burma. In the 50-metre freestyle, Lim, the two-time champion, defended her title again and lowered her games record to 25.69. In her other individual event, Lim finished fourth in the 100-metre freestyle in 56.85. In the 4 × 200-metre freestyle relay, Lim with Quah Ting Wen, Lynette Lim and Tao Li won gold in 8:13.99.