A measurement of the Higgs boson Yukawa coupling to the top quark is presented using proton-proton collision data at
√
s
=
13
 
 
TeV
, corresponding to an integrated luminosity of
137
 
 
fb
−
1
, recorded with the CMS detector. The coupling strength with respect to the standard model value,
Y
t
, is determined from kinematic distributions in
t
¯
t
final states containing
e
e
,
μ
μ
, or
e
μ
pairs. Variations of the Yukawa coupling strength lead to modified distributions for
t
¯
t
production. In particular, the distributions of the mass of the
t
¯
t
system and the rapidity difference of the top quark and antiquark are sensitive to the value of
Y
t
. The measurement yields a best fit value of
Y
t
=
1.16
+
0.24
−
0.35
, bounding
Y
t
<
1.54
at a 95% confidence level.