An electric actuator includes: a drive part (2); a motion conversion mechanism part (3) configured to convert a rotary motion from the drive part (2) to a linear motion in an axial direction parallel with an output shaft (10a) of the drive part (2); a driving force transmission part (4) including a transmission gear mechanism (28) configured to transmit a driving force from the drive part (2) to the motion conversion mechanism part (3); and a motion-conversion-mechanism support part (5) including a double-row bearing (40) configured to support the motion conversion mechanism part (3), wherein the double-row bearing (40) is arranged on one side in the axial direction with respect to the transmission gear mechanism (28).