A universal surgical instrument guide for accommodating surgical instruments to facilitate precise positioning of the surgical instruments using a robotic surgical system, the universal surgical instrument guide comprising: - a body arranged to be mechanically coupled to a robotic arm of the robotic surgical system, the body comprising: - a first channel comprising an interior surface sized and shaped to accommodate a tightening screw that, upon insertion and engaging of the tightening screw, securely attaches the body directly or indirectly to the robotic arm of the robotic surgical system, - a second channel, wherein a diameter of the second channel is greater than a diameter of the first channel, having an interior surface shaped and sized to accommodate a portion of a surgical instrument guide (500,600) sized and shaped to receive one or more surgical instruments, wherein: - the second channel comprises a first opening, wherein a portion of the second channel adjacent to the first opening is threaded such that when the surgical instrument guide (500,600) is inserted in the second channel, threads of the threaded portion of the second channel engage threads on the surgical instrument guide (500,600) to securely hold the surgical instrument guide ( 500,600), and wherein a distal end of the threaded portion of the second opening has a lip to engage with the surgical instrument guide (500,600) to prevent over-threading of the surgical instrument guide, and - the interior surface of the second channel defines an axis such that, when the surgical instrument guide (500,600) is inserted into the universal surgical instrument guide when the threads of the threaded portion of the second channel engage the threads on the surgical instrument guide (500,600), movement of a surgical instrument is constrained along the axis when the surgical instrument is moved within the surgical instrument guide (500,600); and - wherein a navigation marker is attached to universal surgical instrument guide using a fastener inserted into a second opening in the body of universal surgical instrument guide, wherein the second opening is a threaded opening sized and shaped to receive the fastener to attach the navigation marker being used by a navigation camera to track the position of the universal surgical instrument guide; and - one or more alignment pins (225a-c), extending from the body such that the one or more alignment pins (225a-c), upon mechanically coupling the body to the robotic arm, engage one or more openings in the robotic arm such as a tool support of the robotic arm, thereby precisely locating the universal instrument guide relative to the robotic arm. - a body arranged to be mechanically coupled to a robotic arm of the robotic surgical system, the body comprising: - a first channel comprising an interior surface sized and shaped to accommodate a tightening screw that, upon insertion and engaging of the tightening screw, securely attaches the body directly or indirectly to the robotic arm of the robotic surgical system, - a second channel, wherein a diameter of the second channel is greater than a diameter of the first channel, having an interior surface shaped and sized to accommodate a portion of a surgical instrument guide (500,600) sized and shaped to receive one or more surgical instruments, wherein: - the second channel comprises a first opening, wherein a portion of the second channel adjacent to the first opening is threaded such that when the surgical instrument guide (500,600) is inserted in the second channel, threads of the threaded portion of the second channel engage threads on the surgical instrument guide (500,600) to securely hold the surgical instrument guide ( 500,600), and wherein a distal end of the threaded portion of the second opening has a lip to engage with the surgical instrument guide (500,600) to prevent over-threading of the surgical instrument guide, and - the interior surface of the second channel defines an axis such that, when the surgical instrument guide (500,600) is inserted into the universal surgical instrument guide when the threads of the threaded portion of the second channel engage the threads on the surgical instrument guide (500,600), movement of a surgical instrument is constrained along the axis when the surgical instrument is moved within the surgical instrument guide (500,600); and - wherein a navigation marker is attached to universal surgical instrument guide using a fastener inserted into a second opening in the body of universal surgical instrument guide, wherein the second opening is a threaded opening sized and shaped to receive the fastener to attach the navigation marker being used by a navigation camera to track the position of the universal surgical instrument guide; and - one or more alignment pins (225a-c), extending from the body such that the one or more alignment pins (225a-c), upon mechanically coupling the body to the robotic arm, engage one or more openings in the robotic arm such as a tool support of the robotic arm, thereby precisely locating the universal instrument guide relative to the robotic arm.