# List of most massive neutron stars

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| Name | Mass (M$_☉$) | Distance (ly) | Companion class | Mass determination method | Notes |
| PSR J1748-2021B | 2.548+0.047 −0.078 | 27,700 | D | Rate of advance of periastron. | In globular cluster NGC 6440. |
| 4U 1700-37 | 2.44±0.27 | 6,910 ± 1,120 | O6.5Iaf$^+$ | Monte Carlo simulations of thermal comptonization process. | HMXB system. |
| PSR J2017-1614 | 2.4±0.6 | 4,570 | Substellar object | | Black widow pulsar, in a tight 2.3 hour binary. |
| PSR J0952–0607 | 2.35±0.17 | 3,200–5,700 | Substellar object | Radio-measured Shapiro delay | Black widow pulsar. Fastest spinning galactic pulsar. |
| PSR J1311–3430 | 2.15–2.7 | 6,500–12,700 | Substellar object | Spectroscopic and photometric observation. | Black widow pulsar. |
| PSR J1600−3053 | 2.3+0.7 −0.6 | 6,500 ± 1,000 | D | Fourier analysis of Shapiro delay's orthometric ratio. | |
| PSR J2215+5135 | 2.27+0.17 −0.15 | 10,000 | G5V | Innovative measurement of companion's radial velocity. | Redback pulsar. |
| XMMU J013236.7+303228 | 2.2+0.8 −0.6 | 2,730,000 | B1.5IV | Detailed spectroscopic modelling. | In M33, HMXB system. |
| PSR J0751+1807 | 2.10±0.2 | 6,500 ± 1,300 | D | Precision pulse timing measurements of relativistic orbital decay. | |
| PSR J0740+6620 | 2.08±0.07 | 4,600 | D | Range and shape parameter of Shapiro delay. | Most massive neutron star with a well-constrained mass. |
| PSR J0348+0432 | 2.01±0.04 | 2,100 | D | Spectroscopic observation and orbital decay due to radiation of gravitational waves. | |
| PSR J1518+0204B (M5B) | 1.981 | 24,500 | M6-8V? | | In the globular cluster, M5. In a 7 day binary with a low-mass 0.11-0.13 M$_☉$ red dwarf. |
| PSR B1516+02B | 1.94+0.17 −0.19 | 24,500 | D | Rate of advance of periastron. | In globular cluster M5. |
| PSR J1614−2230 | 1.908±0.016 | 3,900 | D | Range and shape parameter of Shapiro delay. | In Milky Way's galactic disk. |
| Vela X-1 | 1.88±0.13 | 6,200 ± 650 | B0.5Ib | Rate of advance of periastron. | Prototypical detached HMXB system. |
| PSR J2222–0137 | 1.831 | 871 | D | | Companion is a white dwarf which is one of the most massive at 1.319 M$_☉$ |
| PSR B1957+20 | 1.81±0.17 | 6,500 | Substellar object | Rate of advance of periastron. | Prototype star of black widow pulsars. |
| SWIFT J1756.9-2508 | 1.8±0.4 | 26,100 | Substellar object | | Hosts one planet, it is notable for orbiting its star in 54 minutes. |