This is a list of disk operating systems in which the acronym DOS is used to form their names. Many of these are simply referred to as "DOS" within their respective communities.

• MS-DOS (since 1981), Microsoft operating system based on 86-DOS for x86-based personal computers
• IBM PC DOS (since 1981), rebranded OEM version of MS-DOS sold by IBM. Identical or almost identical to MS-DOS until PC DOS version 6
• DR-DOS (since 1988), MS-DOS-compatible operating system originally developed by Digital Research
• ROM-DOS (1989), MS-DOS clone by Datalight
• PTS-DOS (since 1993), MS-DOS clone developed in Russia by PhysTechSoft
• FreeDOS (since 1998), open source MS-DOS clone

• 86-DOS (a.k.a. QDOS, created 1980), an operating system developed by Seattle Computer Products for its 8086-based S-100 computer kit, heavily inspired by CP/M
• Concurrent DOS (a.k.a. CDOS, Concurrent PC DOS and CPCDOS) (since 1983), a CP/M-86 and MS-DOS 2.11 compatible multiuser, multitasking DOS, based on Concurrent CP/M-86 developed by Digital Research
• DOS Plus (since 1985), a PC DOS and CP/M-86 compatible multitasking operating system for early x86-based personal computers, based on Concurrent PC DOS 4.1/5.0 by Digital Research
• Multiuser DOS (a.k.a. MDOS), a PC DOS and CP/M-86 compatible multiuser multitasking operating system based on Concurrent DOS by Digital Research
• NetWare PalmDOS, a successor of DR DOS 6.0 specifically tailored for early mobile and palmtop PCs by Novell
• Novell DOS, a multitasking successor of DR DOS 6.0 by Novell
• OpenDOS, a successor of Novell DOS by Caldera

• Atari DOS, from Atari, Inc.
• DOS XL, from Optimized Systems Software
• MyDOS^[1]
• SmartDOS^[1]
• SpartaDOS
• SpartaDOS X
• TOP-DOS^[1]
• Turbo-DOS

• AmigaDOS, disk operating system portion of AmigaOS
• AMSDOS, for Amstrad CPC compatibles
• ANDOS, operating system for the Russian Electronika BK
• Apple DOS, operating system for the Apple II series from late 1978 through early 1983
• Apple ProDOS, name for both ProDOS 8 for the Apple II and ProDOS 16 for the Apple IIGS
• Commodore DOS, for Commodore's 8-bit computers
• Cromemco DOS (CDOS), a CP/M-like operating system
• CSI-DOS, for the Soviet Elektronika BK computers
• DOS (Diskette Operating System), a small OS for 16-bit Data General Nova computers, a cut-down version of their RDOS.
• DEC BATCH-11/DOS-11, the first operating system to run on the PDP-11 minicomputer
• Delta DOS, third party option from Premier Microsystems for the Dragon 32/64
• DIP DOS, the operating system of the Atari Portfolio
• DOS/360, 1966 IBM System/360 mainframe computer Disk Operating System
• DragonDOS, for the Dragon 32/64
• GEMDOS, one of the components of Atari TOS
• IDOS, for the Ivel Ultra Apple II clone
• IS-DOS, for Russian ZX Spectrum clones, developed in 1990 or 1991
• IMDOS, for IMSAI 8080
• MasterDOS, replacement DOS for the SAM Coupé
• MDOS (Micropolis DOS) for S-100
• MDOS, Myarc Disk Operating System for the Geneve 9640
• MSX-DOS, a cross between MS-DOS 1.0 and CP/M developed by Microsoft for the MSX computer standard
• NewDos/80, third-party option for the TRS-80
• Oric DOS, for the Oric-1 home computer
• PTDOS,^[2] for the 1970s Sol-20 from Processor Technology
• SAMDOS, original DOS for the SAM Coupé
• SDOS, for the SWTPC 6800 from the Southwest Technical Products Corporation
• Sinclair QDOS, for the Sinclair QL
• RDOS, a real-time operating system released in 1972 for the Data General Nova and Eclipse minicomputers
• SK*DOS,^[3] for Motorola 68000-based systems
• TR-DOS, for the ZX Spectrum
• TRSDOS, for the Tandy TRS-80 line of 8-bit Zilog Z80 microcomputers
• Xtal DOS for the Tatung Einstein

• DOS (disambiguation)
• DOS 1 (disambiguation)
• DOS 2 (disambiguation)
• DOS 3 (disambiguation)
• DOS 4 (disambiguation)
• DOS 5 (disambiguation)
• DOS 6 (disambiguation)
• DOS 7 (disambiguation)
• DOS 8 (disambiguation)
• DOS 10 (disambiguation)
• DOS 20 (disambiguation)