A bstract A measurement of the time-integrated CP asymmetry in D 0 → K S 0 K S 0 decays is reported. The data correspond to an integrated luminosity of about 2 fb −1 collected in 2015–2016 by the LHCb collaboration in pp collisions at a centre-of-mass energy of 13 TeV. The D 0 candidate is required to originate from a D *+ → D 0 π + decay, allowing the determination of the flavour of the D 0 meson using the pion charge. The D 0 → K + K − decay, which has a well measured CP asymmetry, is used as a calibration channel. The CP asymmetryfor D 0 → K S 0 K S 0 is measured to be $$ {\mathcal{A}}^{CP}\left({D}^0\to {K}_S^0{K}_S^0\right)=\left(4.3\pm 3.4\pm 1.0\right)\%, $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>C</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> </mml:msup> <mml:mfenced> <mml:mrow> <mml:msup> <mml:mi>D</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:mrow> </mml:mfenced> <mml:mo>=</mml:mo> <mml:mfenced> <mml:mrow> <mml:mn>4.3</mml:mn> <mml:mo>±</mml:mo> <mml:mn>3.4</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1.0</mml:mn> </mml:mrow> </mml:mfenced> <mml:mo>%</mml:mo> <mml:mtext>,</mml:mtext> </mml:math> where the first uncertainty is statistical and the second is systematic. This result is combined with the previous LHCb measurement at lower centre-of-mass energies to obtain $$ {\mathcal{A}}^{CP}\left({D}^0\to {K}_S^0{K}_S^0\right)=\left(2.3\pm 2.8\pm 0.9\right)\%. $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>A</mml:mi> <mml:mrow> <mml:mi>C</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> </mml:msup> <mml:mfenced> <mml:mrow> <mml:msup> <mml:mi>D</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:mrow> </mml:mfenced> <mml:mo>=</mml:mo> <mml:mfenced> <mml:mrow> <mml:mn>2.3</mml:mn> <mml:mo>±</mml:mo> <mml:mn>2.8</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.9</mml:mn> </mml:mrow> </mml:mfenced> <mml:mo>%</mml:mo> <mml:mtext>.</mml:mtext> </mml:math>