Here's a look at some of what Mr Trump has done so far
Business regulations
An attempt to cut down on the burden of small businesses.
Described as a "two-out, one-in" approach, the order asked government departments that request a new regulation to specify two other regulations they will drop.
The Office of Management and Budget (OMB) will manage the regulations and is expected to be led by the Republican Mick Mulvaney.
Some categories of regulation will be exempt from the "two-out, one-in" clause - such as those dealing with the military and national security and "any other category of regulations exempted by the Director".
Immediate impact: Wait and see.
Trump moves to cut business regulation
Travel ban
Probably his most controversial action, so far, taken to keep the country safe from terrorists, the president said.
It included:
suspension of refugee programme for 120 days, and cap on 2017 numbers
indefinite ban on Syrian refugees
ban on anyone arriving from seven Muslim-majority countries, with certain exceptions
cap of 50,000 refugees
The effect was felt at airports in the US and around the world as people were stopped boarding US-bound flights or held when they landed in the US.
Immediate impact: Enacted pretty much straightaway. But there are battles ahead. Federal judges brought a halt to deportations, and further lawsuits concerning the constitutionality of the ban are brewing.
Trump border policy: Who's affected?
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Border security
The wall
On Mr Trump's first day as a presidential candidate in June 2015, he made securing the border with Mexico a priority.
He pledged repeatedly at rallies to "build the wall" along the southern border, saying it would be "big, beautiful, and powerful".
Now he has signed a pair of executive orders designed to fulfil that campaign promise.
One order declares that the US will create "a contiguous, physical wall or other similarly secure, contiguous, and impassable physical barrier".
The second order pledges to hire 10,000 more immigration officers, and to revoke federal grant money from so-called "sanctuary cities" which refuse to deport undocumented immigrants.
It remains to be seen how Mr Trump will pay for the wall, although he has repeatedly insisted that it will be fully paid for by the Mexican government, despite their leaders saying otherwise.
Steps before building can start
Executive order, House, Senate, Sign into law
Immediate impact: The Department of Homeland Security has a "small" amount of money available (about $100m) to use immediately, but that won't get them very far. Construction of the wall will cost billions of dollars - money that Congress will need to approve. Senator Majority Leader Mitch McConnell has said the Republican-led Congress will need to come up with $12-$15bn more, and the funding fight - and any construction - will come up against issues with harsh terrain, private land owners and opposition from both Democrats and some Republicans.
The department will also need additional funds from Congress to hire more immigration officers, but the order will direct the head of the agency to start changing deportation priorities. Cities targeted by the threat to remove federal grants will likely build legal challenges, but without a court injunction, the money can be removed.
How exactly will Trump 'build the wall'?
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Two orders, two pipelines
Pipeline
On his second full working day, the president signed two orders to advance construction of two controversial pipelines - the Keystone XL and Dakota Access.
Mr Trump told reporters the terms of both deals would be renegotiated, and using American steel was a requirement.
Keystone, a 1,179-mile (1,897km) pipeline running from Canada to US refineries in the Gulf Coast, was halted by President Barack Obama in 2015 due to concerns over the message it would send about climate change.
The second pipeline was halted last year as the Army looked at other routes, amid huge protests by the Standing Rock Sioux Tribe at a North Dakota site.
Steps before it can happen
Executive memorandum, State Department decision
Immediate impact: TransCanada, the Keystone XL builder, has resubmitted their permit proposal, but the project will likely attract legal battles on the state level. The Army Corps of Engineers will continue its review of the Dakota Access pipeline route, but the executive order could speed up the process - and set the stage for a final route approval by a political appointee.
Keystone XL pipeline: Why is it so disputed?
Dakota Pipeline: What's behind the controversy?
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Instructing federal agencies to weaken Obamacare
obamacare rule
In one of his first actions as president, Mr Trump issued a multi-paragraph directive to the Department of Health and Human Services and other federal agencies involved in managing the nation's healthcare system.
The order states that agencies must "waive, defer, grant exemptions from, or delay" any portions of the Affordable Care Act that creates financial burden on states, individuals or healthcare providers.
Although the order technically does not authorise any powers the executive agencies do not already have, it's viewed as a clear signal that the Trump administration will be rolling back Obama-era healthcare regulations wherever possible.
Steps before it can happen
Executive order, House, Senate, Sign into law
Immediate impact: Not much, unless it's interpreted very broadly by the new Health Secretary and individual states. But it's probably more likely to influence how Congress proceeds with its repeal efforts.
Can Obamacare be repealed?
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Re-instating a ban on international abortion counselling
Abortion
What's called the Mexico City policy, first implemented in 1984 under Republican President Ronald Reagan, prevents foreign non-governmental organisations that receive any US cash from "providing counselling or referrals for abortion or advocating for access to abortion services in their country", even if they do so with other funding.
The ban, derided as a "global gag rule" by its critics, has been the subject of a political tug-of-war ever since its inception, with every Democratic president rescinding the measure, and every Republican bringing it back.
Anti-abortion activists expected Mr Trump to act quickly on this - and he didn't disappoint them.
Executive memorandum
Immediate impact: The policy will come into force as soon as the Secretaries of State and Heath write an implementation plan and apply to both renewals and new grants. It will be much broader than the last time the rule was in place - the Guttmacher Institute, Kaiser Family Foundation and Population Action International believe the order, as written, will apply to all global health funding by the US, instead of only reproductive health or family planning.
Trump's order on abortion policy: What does it mean?
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Freezing federal government hiring
White house feeze
On Mr Trump's first full workday in the White House he issued a directive to federal agencies to halt any new government hiring.
He told reporters who had gathered for the signing that the freeze would not affect military spending.
The directive is part of Mr Trump's effort to reduce government debts and decrease the size of the federal workforce.
During his campaign, he frequently railed against government bureaucracy, and vowed to "drain the swamp" of corrupt governance.
Executive order
Immediate impact: A hiring freeze is immediate, and is expected to last 90 days. The order allows exceptions under broad categories, including military, public safety, as well as case by case exceptions by the Office of Management and Budget.
Has the federal workforce really 'dramatically increased'?
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TPP
Withdrawing from the Trans-Pacific Partnership
The Trans-Pacific Partnership, once viewed as the crown jewel of Barack Obama's international trade policy, was a regular punching bag for Mr Trump on the campaign trail (although he at times seemed uncertain about what nations were actually involved).
The deal was never approved by Congress so it had yet to go into effect in the US.
Therefore the formal "withdrawal" is more akin to a decision on the part of the US to end ongoing international negotiations and let the deal wither and die.
Executive memorandum
Immediate impact: Takes effect immediately. In the meantime, some experts are worried China will seek to replace itself in the deal or add TPP nations to its own free trade negotiations, the Regional Comprehensive Economic Partnership (RCEP), excluding the US.
but still commendable behavior
