{{Misja Space Shuttle infobox 
|  mission      = STS-81
|  insignia     = Sts-81-patch.png
|  shuttle      = Atlantis
|  launch pad   = 39-B 
|  launch       = 12 stycznia 1997, 09:27:23 UTC
|  landing      = KSC, Pas startowy 3
|  duration     = 10 dni, 4 godz., 56 min, 30 sek 
|  altitude     = 184 mile morskie (296 km) 
|  inclination  = 
|  distance     = 6,6 mln km 
|  crew photo   = STS-81_crew.jpg
|  crew caption = 
|  previous     = STS-80 
|  next         = STS-82
}}

'''STS-81''' (ang. ''Space Transportation System'') - to misja amerykańskiego wahadłowca Atlantis na rosyjską stację orbitalną Mir.

== Załoga ==
*Michael Baker (4), dowódca
*Brent Jett (2), pilot 
*John Grunsfeld (2), specjalista misji
*Marsha Ivins (4), specjalista misji
*Peter Wisoff (3), specjalista misji

=== Przywieziony członek załogi Mira ===
*Jerry Linenger (2), specjalista misji

=== Odwieziony członek załogi Mira ===
*John Blaha (5)

<small>(liczba w nawiasie oznacza ilość lotów odbytych przez każdego z astronautów)</small>

{{Infobox Space mission 
| mission_name = STS-81
| insignia     = Sts-81-patch.png
| shuttle      = Atlantis
| launch_pad   = 39-B
| launch       = January 12, 1997, 09:27:23 UTC
| landing      = KSC, Runway 3
| duration     = 10 days, 4 hours, 56 minutes, 30 seconds
| altitude     = 184 statute miles (296 km)
| inclination  = 51.60 degrees
| distance     = 4.1 million statute miles (6.6 million km)
| crew_photo   = STS-81_crew.jpg
| crew_caption = 
| previous     = 45px|STS-80|
| next         = 35px|STS-82
}}

'''STS-81''' was a ''Atlantis'' mission to the Mir space station. 

==Crew==
*Michael A. Baker (4), Mission Commander 
*Brent W. Jett, Jr. (2), Pilot 
*Peter J.K. Wisoff (3), Mission Specialist 1 
*John M. Grunsfeld (2), Mission Specialist 2 
*Marsha S. Ivins (4), Mission Specialist 3 

====Launched and stayed on Mir====
*Jerry M. Linenger (2), Mission Specialist 4

====Landed and returned from Mir====
*John E. Blaha (5), Mission Specialist 4

==Mission parameters==
*'''Mass:''' 2,250 kg
*'''Perigee:''' 380 km
*'''Apogee:''' 392 km
*'''Inclination:''' 51.6° 
*'''Period:''' 92.2 min

===Fifth Mir docking mission===
*'''Docked''': January 15, 1997, 03:54:49 UTC
*'''Undocked''': January 20, 1997, 02:15:44 UTC
*'''Time Docked''': 4 days, 22 h, 20 min, 55 s

==Mission highlights==

STS-81 was the fifth of nine planned missions to Mir and the second one involving an exchange of U.S. astronauts. Astronaut John Blaha, who had been on Mir since September 19, 1996, was replaced by astronaut Jerry Linenger. Linenger spent more than four months on Mir. He returned to Earth on Space Shuttle Mission STS-84.

Atlantis carried the SPACEHAB double module providing additional middeck locker space for secondary experiments. During the five days of docked operations with Mir, the crews transferred water and supplies from one spacecraft to the other. A spacewalk by Linenger and one of his Russian cosmonaut crewmates will be after Atlantis departs.

The STS-81 mission included several experiments in the fields of advanced technology, Earth sciences, fundamental biology, human life sciences, microgravity, and space sciences. It was hoped that data would supply insight for the planning and development of the International Space Station, Earth-based sciences of human and biological processes, and the advancement of commercial technology.