Here $${\underline{M}}$$
M
̲
denotes a pair (M, A) of a manifold and a subset (e.g. $$A=\partial M$$
A
=
∂
M
or $$A=\varnothing $$
A
=
∅
). We construct for each $${\underline{M}}$$
M
̲
its motion groupoid$$\textrm{Mot}_{{\underline{M}}}$$
Mot
M
̲
, whose object set is the power set $$ {{\mathcal {P}}}M$$
P
M
of M, and whose morphisms are certain equivalence classes of continuous flows of the ‘ambient space’ M, that fix A, acting on $${{\mathcal {P}}}M$$
P
M
. These groupoids generalise the classical definition of a motion group associated to a manifold M and a submanifold N, which can be recovered by considering the automorphisms in $$\textrm{Mot}_{{\underline{M}}}$$
Mot
M
̲
of $$N\in {{\mathcal {P}}}M$$
N
∈
P
M
. We also construct the mapping class groupoid$$\textrm{MCG}_{{\underline{M}}}$$
MCG
M
̲
associated to a pair $${\underline{M}}$$
M
̲
with the same object class, whose morphisms are now equivalence classes of homeomorphisms of M, that fix A. We recover the classical definition of the mapping class group of a pair by taking automorphisms at the appropriate object. For each pair $${\underline{M}}$$
M
̲
we explicitly construct a functor $${\textsf{F}}:\textrm{Mot}_{{\underline{M}}} \rightarrow \textrm{MCG}_{{\underline{M}}}$$
F
:
Mot
M
̲
→
MCG
M
̲
, which is the identity on objects, and prove that this is full and faithful, and hence an isomorphism, if $$\pi _0$$
π
0
and $$\pi _1$$
π
1
of the appropriate space of self-homeomorphisms of M are trivial. In particular, we have an isomorphism in the physically important case $${\underline{M}}=([0,1]^n, \partial [0,1]^n)$$
M
̲
=
(
[
0
,
1
]
n
,
∂
[
0
,
1
]
n
)
, for any $$n\in {\mathbb {N}}$$
n
∈
N
. We show that the congruence relation used in the construction $$\textrm{Mot}_{{\underline{M}}}$$
Mot
M
̲
can be formulated entirely in terms of a level preserving isotopy relation on the trajectories of objects under flows—worldlines (e.g. monotonic ‘tangles’). We examine several explicit examples of $$\textrm{Mot}_{{\underline{M}}}$$
Mot
M
̲
and $$\textrm{MCG}_{{\underline{M}}}$$
MCG
M
̲
demonstrating the utility of the constructions.