This plant occurs in coastal areas and in the Hajar Mountains (Jongbloed et al. 2003) and has been found to occur in Wadi Wurayah National Park, Fujairah (Feulner 2016). It also occurs at Jebel Ali along the Arabian Gulf Coast. The estimated EOO of this species is 2,646 km². Globally, Ophioglossum polyphyllum is distributed across Africa and southwest Asia, eastwards to India and southwards to South Africa (Board of Trustees, RGB Kew 2018). In Europe it occurs only on the Canary Islands (Christenhusz et al. 2017). It is also distributed in Central America and Australia (Board of Trustees, RGB Kew 2018).

In the UAE, this species is found in Wadi Naqab and in the Ru'us al-Jibal Mountains in the UAE (Jongbloed et al. 2003, Feulner 2011). Karim and Fawzi (2007) recorded it from Wadi Sha'am. The extent of occurrence (EOO) of this species is estimated at less than 294 km². This species is widespread in the tropics of the Old World. It occurs in tropical Africa from Egypt to South Africa and Madagascar (APD 2019), through the Arabian Peninsula (Yemen, Oman, the UAE) to Pakistan, India and Sri Lanka, and Southeast Asia (Board of Trustees, RBG Kew 2018). It is introduced in Australia.

This species is common along the Arabian Gulf coast of the UAE, from west of Abu Dhabi city to Ras Al-Khaimah (Jongbloed et al. 2003). The species has been recorded from Wadi Wurayah, however the origin of the species here is uncertain, and is likely to be the result of accidental introduction (Feulner 2016). Al Mehairbi et al. (2019) show a very much broader distribution for this species, across almost the entire UAE; it is thought that, if correct, this broader distribution may be the result of introduction. Globally, the species is considered to be native to the Mediterranean and throughout most of sub-Saharan Africa, east through the Middle East and Indian sub-continent to China and to Southeast Asia, south to Australia (The Board of Trustees of the Royal Botanic Gardens, Kew 2019). It occurs as a non-native in parts of Europe, the Pacific island states and through South and Central America, north to parts of the United States (The Board of Trustees of the Royal Botanic Gardens, Kew 2019). Within the Arabian Peninsula, this species is described as widespread and weedy in Saudi Arabia (Chaudhary 2001, Norton et al. 2009), common in Bahrain, Qatar (Norton et al. 2009), Oman (Ghazanfar 1992) and the United Arab Emirates (Western 1989, Jongbloed et al. 2003, Norton et al. 2009) and widespread in Yemen (Wood 1977).

The species is found at higher elevations along connected high elevation ridges in the 'Olive Mountains' of the UAE. This species was first recorded for the UAE in 1997 at sites including the summit of Jebel Qitab (at c. 1,000 m asl), and above Wadi al-Iyeli; at each of these localities approximately two dozen specimens were present in adjacent ravines, and observations suggested that limited numbers were present in the intervening area (Feulner 1997). In general, it is restricted to the highest ridges of the Hajar Mountains southwest of Fujairah above 600 m (G.R. Feulner, in litt, MEW 2010, Feulner 2014). Records from the ""Olive Highlands"" area include the higher ridges above Wadi Mayy, Wadi Hayl and Wadi Saham, on north-facing cliffs of Jebel Al-Iyeli and on the northern slopes and ravines of Jebel Sfai (Feulner 2014). Individual small specimens have been found at wadi level in Wadi Hayl (M.A.R. Khan pers. comm. in Feulner 2014). The only other records are of two small trees (<1.5 metres tall) on the northern slopes of Jebel Jabsah, and north of Wadi Ham on the outskirts of Fujairah city (Feulner 2014). The species is absent from Wadi Wurayah National Park (Feulner 2016) and from the Ru's al-Jibal (Feulner 2011). The EOO is less than 200 km². The AOO has not been measured as detailed locality records are not available, but it is likely to also be 200 km². It is considered to be native to the UAE. The species has been very widely cultivated so it is difficult to determine its full native range, but currently it is considered native to parts of Africa, Europe and western Asia.

Within the UAE, it is considered to be widespread although scattered (Brown et al. 2007). It can be found on coastal sands and plains, including Taweela and Al Jazeera al-Hamra (Brown et al. 2007). It has also been recorded from offshore islands of Abu Dhabi (Sakkir et al. 2017). Globally, this species occurs from north-east Africa to the Arabian Peninsula and India (Board of Trustees, RBG Kew 2019).

The majority of occurrences of this species within the UAE are likely to be of migrant individuals on passage to and from the breeding grounds in September-November and March-April (Richardson 1990, Pedersen et al. 2017). It is also a common wintering bird in the country (Pedersen et al. 2017). Since 1993, there was a small resident population of about 20 pairs in the UAE, which bred on Taweela Island/Ras Ghanada (Abu Dhabi) and Siniyah Island (Umm al-Quwain), as well as along the coast from Umm al-Quwain to Ras al-Khaimah emirates (Richardson and Aspinall 1998, Jennings 2010, Pedersen et al. 2017). However, it is now believed that the species no longer breeds regularly in the UAE, if it still breeds at all (R. Sheldon;in litt.;2019). There hasn't been sufficient surveying work, though, to confirm its disappearance from the country as a breeding species, and it is quite possible that there could be individuals breeding in unsurveyed areas. Therefore, for this process it is tentatively treated as being still extant.

The majority of occurrences of this species within the UAE are likely to be of wintering birds and migrant individuals on passage to and from the breeding grounds. Numbers are highest between September and early April, when the species is common in arid zones throughout the country (Aspinall and Porter 2011, Pedersen et al. 2017). Individuals wintering in or passing through the UAE breed in southern central Asia.

This species is an uncommon to fairly common resident in the northern highlands as well as in the eastern part of the UAE. Occasionally, individuals stop in the country during migration or for wintering (Pedersen et al. 2017). The occurrence of wintering individuals in the lowland plains along the coast might be of local altitudinal migrants within the country (Jennings 2010).

The majority of occurrences of this species within the UAE are likely to be of wintering birds or migrant individuals on passage to and from the breeding grounds. Numbers are highest between mid-September and mid-April, occasionally to early May, when the species is fairly common to common throughout the country (Pedersen et al. 2017). Individuals wintering in or migrating through the UAE breed in central-eastern Asia.